chemistry assignment 4th week class 9

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Class 9 Chemistry Assignments

We have provided below free printable Class 9 Chemistry Assignments for Download in PDF. The Assignments have been designed based on the latest NCERT Book for Class 9 Chemistry . These Assignments for Grade 9 Chemistry cover all important topics which can come in your standard 9 tests and examinations. Free printable Assignments for CBSE Class 9 Chemistry , school and class assignments, and practice test papers have been designed by our highly experienced class 9 faculty. You can free download CBSE NCERT printable Assignments for Chemistry Class 9 with solutions and answers. All Assignments and test sheets have been prepared by expert teachers as per the latest Syllabus in Chemistry Class 9. Students can click on the links below and download all Pdf Assignments for Chemistry class 9 for free. All latest Kendriya Vidyalaya Class 9 Chemistry Assignments with Answers and test papers are given below.

Chemistry Class 9 Assignments Pdf Download

We have provided below the biggest collection of free CBSE NCERT KVS Assignments for Class 9 Chemistry . Students and teachers can download and save all free Chemistry assignments in Pdf for grade 9th. Our expert faculty have covered Class 9 important questions and answers for Chemistry as per the latest syllabus for the current academic year. All test papers and question banks for Class 9 Chemistry and CBSE Assignments for Chemistry Class 9 will be really helpful for standard 9th students to prepare for the class tests and school examinations. Class 9th students can easily free download in Pdf all printable practice worksheets given below.

Topicwise Assignments for Class 9 Chemistry Download in Pdf

Advantages of Class 9 Chemistry Assignments

• As we have the best and largest collection of Chemistry assignments for Grade 9, you will be able to easily get full list of solved important questions which can come in your examinations.
• Students will be able to go through all important and critical topics given in your CBSE Chemistry textbooks for Class 9 .
• All Chemistry assignments for Class 9 have been designed with answers. Students should solve them yourself and then compare with the solutions provided by us.
• Class 9 Students studying in per CBSE, NCERT and KVS schools will be able to free download all Chemistry chapter wise worksheets and assignments for free in Pdf
• Class 9 Chemistry question bank will help to improve subject understanding which will help to get better rank in exams

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We provide here Standard 9 Chemistry chapter-wise assignments which can be easily downloaded in Pdf format for free.

You can click on the links above and get assignments for Chemistry in Grade 9, all topic-wise question banks with solutions have been provided here. You can click on the links to download in Pdf.

We have provided here topic-wise Chemistry Grade 9 question banks, revision notes and questions for all difficult topics, and other study material.

We have provided the best collection of question bank and practice tests for Class 9 for all subjects. You can download them all and use them offline without the internet.

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Assignments For Class 9 Chemistry

Assignments for Class 9 Chemistry have been developed for Standard 9 students based on the latest syllabus and textbooks applicable in CBSE, NCERT and KVS schools. Parents and students can download the full collection of class assignments for class 9 Chemistry from our website as we have provided all topic wise assignments free in PDF format which can be downloaded easily. Students are recommended to do these assignments daily by taking printouts and going through the questions and answers for Grade 9 Chemistry. You should try to do these test assignments on a daily basis so that you are able to understand the concepts and details of each chapter in your Chemistry book and get good marks in class 9 exams.

Assignments for Class 9 Chemistry as per CBSE NCERT pattern

All students studying in Grade 9 Chemistry should download the assignments provided here and use them for their daily routine practice. This will help them to get better grades in Chemistry exam for standard 9. We have made sure that all topics given in your textbook for Chemistry which is suggested in Class 9 have been covered ad we have made assignments and test papers for all topics which your teacher has been teaching in your class. All chapter wise assignments have been made by our teachers after full research of each important topic in the textbooks so that you have enough questions and their solutions to help them practice so that they are able to get full practice and understanding of all important topics. Our teachers at https://www.assignmentsbag.com have made sure that all test papers have been designed as per CBSE, NCERT and KVS syllabus and examination pattern. These question banks have been recommended in various schools and have supported many students to practice and further enhance their scores in school and have also assisted them to appear in other school level tests and examinations. Its easy to take print of thee assignments as all are available in PDF format.

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• Parents will be able to take print out of the assignments and give to their child easily.

All free Printable practice assignments are in PDF single lick download format and have been prepared by Class 9 Chemistry teachers after full study of all topics which have been given in each chapter so that the students are able to take complete benefit from the worksheets. The Chapter wise question bank and revision assignments can be accessed free and anywhere. Go ahead and click on the links above to download free CBSE Class 9 Chemistry Assignments PDF.

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You can get free PDF downloadable assignments for Grade 9 Chemistry from our website which has been developed by teachers after doing extensive research in each topic.

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Chemistry Assignment Class 9 Answer & Solution 2021

May 24, 2021 bdexam-aid Assignment , dshe.gov.bd assignment 0

Chemistry Assignment Class 9 Answer 4th week 2021  has been uploaded in our website immediately after the publication of 4th week assignment by DSHE. Students of Class 9 are recently working with their chemistry Assignment. According to the assignment syllabus given by DSHE, we have given Chemistry Assignment Class 9 Answer sample. After viewing this sample Chemistry assignment, you can prepare your own. In our website, we have described in full length about Chemistry Assignment Class 9 Answer. Read this post carefully from the beginning . 

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Chemistry Assignment Solution

According to the Google search records, we come to know that students all over the country are searching for Chemistry Assignment solutions. That is why we are going to show you a sample chemistry assignment solution. By seeing the solution, you may grow ability to prepare your own assignment too. As a matter of fact, preparing assignment for the first time is not at all easy. Therefore, we have come to help you prepare your assignment effectively. The purpose of this post is purely instructive. Let us see Chemistry Assignment Class 9 Answer & Solution. 

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Class 9 Chemistry Assignment 2021 Topics

Directorate of Secondary and Higher Education published assignment syllabus on the first of November. Immediately after the authority published the syllabus we have given it in our website. You see see the syllabus and assignments plan at dshe.gov.bd 2020 Syllabus. As chemistry subject, the authority has announced several questions for class 9. Let us just cite those questions so that we may give you a sample answer.

As Chemistry assignment topics the authority has published some topics. The firs week chemistry assignment class 9 includes first three chapters. And, the first chemistry assignment topic is the separation of Salt from sands. The class 9 students have to prepare an assignment on the topics. To put it clearly, the students have to show how to separate salt from the sand in practical way. If we put that in Bangla it goes like this : ( হাতে কলমে লবণ ও বালির মিশ্রণ পৃথক করে দেখতে হবে ).

dshe.gov.bd Syllabus 2020 PDF | NCTB Short Syllabus 2020

Chemistry Assignment Question Solution

It is not very difficult to prepare assignment on this topics. But before going to prepare your assignment you need to know about the experiment. After that, you can start preparing your assignment following our instructions. Earlier, we have described how you would prepare an effective assignment. For making an effective assignment, we recommend you to see our post related to DSHE Assignments. 

Apart from that, we have showed you how you will design assignment cover page. Further, we have given you assignment front page sample. By showing the assignment sample you can design one for you. But for now, we are doing Chemistry Assignment Class 9 Answer. You can have a look at the following answer.

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Class 9 Chemistry Assignment PDF

For your convenience, we have uploaded the chemistry assignment class 9 answer PDF. You can download Chemistry Assignment Answer for your offline use. Have a look below to download the Chemistry Assignment Class 9 Answer PDF file. 

Download Chemistry Assignment Class 9 Answer PDF

Effective Assignment Writing for Class 9

When you write your practical notebooks for your examination, you have to do some steps. For example, when you do chemistry practical, you need to know the experiment. For doing an assignment, you have to change the layout of working. First of all, you have to write down the topic name at the top. Then you have to write an introduction what are you going to write. Further, you have to write about the experiment apparatuses you need. After that, you have to write about steps of experiment. In the ending, you have to write your conclusion or statement. That is all.

Have a good luck. For improving your assignment, you can follow our website . Because we are working with high school assignment nowadays. Moreover, we have a long experience of preparing good assignment. So, you have in your hands Chemistry Assignment Class 9 Answer now. 

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4th Week Class 9 Chemistry Assignment Answer & Syllabus

4th Week Class 9 Chemistry Assignment Answer & Syllabus ! The Directorate of Secondary and Higher Education (www.dshe.gov.bd) board official website publish Class 9 Chemistry Assignment Syllabus for 4 th Week as soon as possible. After publishing the Class Nine Assignment Syllabus and Question, the Class 9 students are searching for 100% correct Question Solution Answer for Class 9 Chemistry Assignment 2020.

So, we hope this content is very much interested for our Class 9 students. Because today we are going to write all the important information about the Class 9 Chemistry Assignment Answer 2020. So, staying with us and regally visit our website.

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Why Class 9 Chemistry Assignment Question Syllabus & Answer is so important?

This year, the Bangladesh Education Board don’t take any kinds of exam to promote their student class level for COVID-19. But, they are thinking about their student future. So, they are arranging a simple way to promote their students by Assignment System. So, it is very important to submit all assignments in due time.

Class 9 Chemistry Assignment Syllabus 4 th Week:

The authority of the Bangladesh education board not published yet, the “Week 4 Chemistry Assignment for Class 9 Syllabus”. When they published, we update here instantly.

Download PDF: 4th Week Class 9 Assignment 2020 Question Syllabus

4 th Week Chemistry Assignment Answer for Class 9:

This is very important for every Class Nine students to submit their fourth week Class 9 Chemistry Assignment Answer 2020. So, they are looking for the best solution of 4 th week Class 9 Chemistry Assignment.

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What is the Official website for Class 9 Assignment Answer Download 2020?

The official website of the Directorate of Secondary and Higher Education (www.dshe.gov.bd) officially published all Classes Answers like Class 6 Assignment Syllabus & Answer, Class 9 Assignment Syllabus & Answer, Class 8 Assignment Syllabus & Answer, and Class 9 Assignment Syllabus & Answer. In this content, we only write about Class Nine Chemistry Assignment Answers/Solutions. But, you want to know about the Class 6, 7, 8, 9 Assignment Syllabus & Answers. Just click the above link. If you want to get subject wise Class Six Assignment Answer 2020, Just follow below.

How to Write Class 9 Chemistry Assignment Answer 2020?

Everybody has known that the Bangladesh Education Board close all Schools, colleges & universities for Corona Virus. So, there is no way to Verification sorting, which students is good and which students are medium and bad. So, the Directorate of Secondary and Higher Education board wants to make their Class 6 to Class 9 Student next class roll by Assignment system. So, it is very important to write 100% correct Class 9 Assignment Answer and submit it properly.

Necessary Preparation

It is very important to the student of all classes including Class 9, have to make a mental preparation before starting to write down assignments answer. It is very important to make the assignment clean, clear, beautiful and attractive for good marks. Because it is said, ‘First philosophy then quality judgment’. So make an appropriate assignment you need to be focused on your work.

First, take some clean papers. Make a margin on them. Then start writing with a clear hand. Try to keep the words clean and easy to read. Don’t double write on it. And the most important thing for the assignment is the cover page. You have to take a page where your name, class, rolls, subject, assignment title will be written. And always give accurate answers in the assignment. Don’t make the answers very short or over lengthy, because it will make your teacher irritated and you won’t get a good mark.

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NCERT Solutions for Class 9 Science Chapter 4 Structure of Atom

NCERT Solutions Class 9 Science Chapter 4 Structure of the Atom – Here are all the NCERT solutions for Class 9 Science Chapter 4. This solution contains questions, answers, images, step by step explanations of the complete Chapter 4 titled Structure of the Atom of Science taught in class 9. If you are a student of class 9 who is using NCERT Textbook to study Science, then you must come across Chapter 4 Structure of the Atom. After you have studied lesson, you must be looking for answers of its questions. Here you can get complete NCERT Solutions for Class 9 Science Chapter 4 Structure of the Atom in one place. For a better understanding of this chapter, you should also see Chapter 4 Structure of the Atom Class 9 notes , Science.

Topics and Sub Topics in Class 9 Science Chapter 4 Structure of Atom:

• Structure of Atom
• Charged Particles in Matter
• The Structure of an Atom
• How are Electrons Distributed in Different Orbits (Shells)?
• Atomic Number and Mass Number

These solutions are part of NCERT Solutions for Class 9 Science . Here we have given Class 9 NCERT Science Text book Solutions for Chapter 4 Structure of Atom.

In-Text Questions Solved 

NCERT Textbook for Class 9 Science – Page 47 Question 1. What are canal rays? Answer:  Canal rays are positively charged radiations which led to the discovery of positively charged sub-atomic particle called proton.

Question 2. If an atom contains one electron and one proton, will it carry any charge or not? Answer:  The atom will be electrically neutral as one – ve charge balances one + ve charge.

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• RD Sharma Class 9 Solutions

Class 9 Science NCERT Textbook – Page 49 Question 1. On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole. Answer:  According to Thomson’s model of an atom (i) An atom consists of a positively charged sphere and the electrons are embedded in it, (ii) The negative and positive charges are equal in magnitude. So the atom is electrically neutral.

Question 2. On the basis of Rutherford’s model of an atom, which sub-atomic particle is present in the nucleus of an atom? Answer:  As per Rutherford’s model of an atom, the protons which are positively charged are present in the nucleus of an atom.

Formulae Handbook for Class 9 Maths and Science Educational Loans in India

Question 4. What do you think would be the observation if the a-particle scattering experiment is carried out using a foil of a metal other than gold? Answer:  On using any metal foil, the observations of the a-particle scattering experiment would remain the same as all atoms would have same structure.

Question 2. If K and L shells of an atom are full, then what would be the total number of electrons in the atom? Answer:  K shell can hold 2 electrons and L shell can hold 8 electrons.When both the shells are full, there will be (8 + 2) 10 electrons in the atom.

Questions from NCERT Text Book

Question 2. What are the limitations of J.J. Thomson’s model of the atom? Answer:  According to J.J. Thomson’s model of an atom, the electrons are embedded all over in the positively charged spheres. But experiments done by other scientists showed that protons are present only in the centre of the atom and electrons are distributed around it.

Question 3. What are the limitations of Rutherford’s model of the atom? Answer:  According to Rutherford’s model of an atom the electrons are revolving in a circular orbit around the nucleus. Any such particle that revolves would undergo acceleration and radiate energy. The revolving electron would lose its energy and finally fall into the nucleus, the atom would be highly unstable. But we know that atoms are quite stable.

Question 6. Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements. Answer:  The rules for writing of distribution of electrons in various shells for the first eighteen elements are: (i) The maximum number of electrons present in a shell is given by the formula-2 n 2 ∵ n = orbit number i.e., 1, 2, 3 ∵ Maximum number of electrons in different shells are: K shell n = 1 2n 2 => 2(1) 2 = 2 L shell n = 2 2n 2 => 2(2) 2 = 8 M shell n = 3 2n 2 => 2(3) 2 = 18 N shell n = 4 2n 2 => 2(4) 2 = 32 (ii) The maximum number of electrons that can be accommodated in the outermost orbit is 8. (iii) Electrons are not accommodated in a given shell unless the inner shells are filled. (Shells are filled step-wise).

Question 7. Define valency by taking examples of silicon and oxygen. Answer:  Valency is the combining capacity of an atom. Atomic number of oxygen = 8 Atomic number of silicon = 14 K L M Electronic configuration of oxygen = 2 6 – Electronic configuration of silicon =2 8 4 In the atoms of oxygen the valence electrons are 6 (i.e., electrons in the outermost shell). To fill the orbit, 2 electrons are required. In the atom of silicon, the valence electrons are 4. To fill this orbit 4 electrons are required. Hence, the combining capacity of oxygen is 2 and of silicon is 4. i.e., Valency of oxygen = 2 Valency of silicon = 4

Question 9. Na + has completely filled K and L shells. Explain. Answer:  Sodium atom (Na), has atomic number =11 Number of protons =11 Number of electrons = 11 Electronic configuration of Na = K L M – 2 8 1 Sodium atom (Na) looses 1 electron to become stable and form Na + ion. Hence it has completely filled K and L shells.

Question 12. If Z = 3, what would be the valency of the element? Also, name the element. Answer:  Z = 3, (i.e, atomic number —> z) ∴ Electronic configuration = 2, 1 Valency = 1 Name of the element is lithium.

Question 13. Composition of the nuclei of two atomic species X and Y are given as under X – Y Protons =6 6 Neutrons = 6 8 Give the mass number of X and Y. What is the relation between the two species? Answer:  Mass number of X = Protons + Neutrons = 6 + 6 = 12 Mass number of Y = Protons + Neutrons = 6 + 8 = 14 As the atomic number is same i.e., = 6. [atomic number = number of protons]. Both X and Y are isotopes of same element.

Question 14. For the following statements, write T for True and F for False. (a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons. (b) A neutron is formed by an electron and a proton combining together. Therefore,it is neutral. (c) The mass of an electron is about 1/2000 times that of proton. (d) An isotope of iodine is used for making tincture iodine, which is used as a medicine. Answer:  (a) False (b) False (c) True (d) False

Put tick against correct choice and cross (x) against wrong choice in questions 15, 16 and 17. Question 15. Rutherford’s alpha-particle scattering experiment was responsible for the discovery of (a) Atomic nucleus (c) Proton (b)Electron (d)neutron Answer:  (a) Atomic nucleus

Question 16.Isotopes of an element have (a) the same physical properties (c) different number of neutrons (b)different number of neutrons (d) different atomic numbers. Answer:  (c) different number of neutrons

Question 17. Number of valence electrons in Ct ion are : (a) 16 (b) 8 (c) 17 (d) 18 Answer:  (b) 8

Question 18. Which one of the following is a correct electronic configuration of sodium? (a) 2, 8 (b) 8, 2, 1 (c) 2, 1, 8 (d) 2, 8, 1 Answer:  (d) 2, 8, 1

NCERT Solutions for Class 9 Science Chapter 4 Structure of the Atom (Hindi Medium)

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NCERT Solutions for Class 9 Science Chapter 4 Multiple Choice Questions

NCERT Solutions for Class 9 Science Chapter 4 Very Short Answer Type Questions

Question 2. Why are some elements chemically inert? Answer:  Because their outermost shell is completely filled.

Question 3. Why is atom electrically neutral? Answer:  It has same number of protons and electrons, (positive charge = negative charge).

Question 4. What is the charge and mass of a-particles? Answer:  Charge is + 2 Mass is 4 a.m.u.

Question 5. What are valence electrons? Answer:  Electrons present in the outermost shell of an atom are called valence electrons.

Question 6. An atom has atomic number 12, what is its valency and name the element? Answer:  Atomic number = 12 ∴ Protons = Electrons = 12 Electrons Configuration = K L M -2 8 2 ∴ Valency = 2 Element is magnesium.

Question 7. Find the number of neutrons in 27 13 X. Answer:  Mass number = 27 ∴ p + n = 27 p = 13, (Atomic No. = Number of protons) ∴ 13 + n = 27 ∴ n = 14 ∴ Neutron =14

Question 8. Where is the mass of atoiji concentrated? Answer:  Mass of an atom is concentrated in nucleus.

Question 9. Name two elements with same number of protons and neutrons? Answer:  Carbon (Protons = Neutrons = 6) Oxygen (Protons = Neutrons = 8)

Question 11. Name the isotope used for treatment of cancer. Answer:  Isotope of cobalt.

Question 12. AZX What does this symbol represent? Answer:  X —> Symbol of element A —> Mass number Z —> Atomic number

Question 13. Can the value of ‘Z’ be same for two different atoms? Answer:  No, (Z = atomic number), two different atoms cannot have same atomic number.

Question 14. Can the value of A’ be same for two different atom? Answer:  Yes, it can be e.g. Ca and Ar has A-40 (i.e., mass number).

NCERT Solutions for Class 9 Science Chapter 4 Short Answer Type Questions

Question 1. Name the scientist who discovered protons and neutrons in an atoms. Answer:  Protons were discovered by E. Goldstein in 1866 and neutrons were discovered by J, Chadwick in 1932.

Question 2. What is the contribution of Bohr and Bury together in the structure of atom’s explanation? Answer:  Both Bohr and Bury gave the distribution of electrons into different atoms by giving the formula 2n 2 , where n = shell number.

Question 4. What is an octate? Why would atoms want to complete their octate? Answer:  When the outermost shell of an atom i.e., L, M or N are completely filled with 8 electrons in the shell, it is said an octate. Atoms would want to complete their octate because they want to become stable.

Question 5. Find the valency of 14 7 N and 35 17 Cl. Answer:  The atomic number of nitrogen = 7, No. of protons = 7, No. of electrons = 7 Electronic configuration = K L M =2 5 – Valency = 3 Because either it will gain three electrons or share 3 electrons to complete its octate. The atomic number of chlorine = 17, p = 17, e=17 Electronic configuration = K L M= 2 8 7 Valency = 1 Because it will gain 1 electron to complete its octate.

Question 13. Number of protons and electrons are same in an atom. Then why is it wrong to say that atomic number of an atom is equal to its number of electrons. Answer:  Atomic number ≠ Number of electrons, although number of protons = number of electrons because the electron’s number can change in an atom by loss, or gain of it. But the proton’s number remain constant (as it does not take part in loss or gain).

Question 14. An atom is electrically neutral, on loss or gain of electrons why does it become charged? Answer:  An atom is electrically neutral because of same number of protons and electrons. But it becomes charged, to become stable atom, loses or gains electrons. Hence, Number of protons ≠ Number of electrons If it loses electrons p > e; hence +ve charge is obtained. If it gains electrons e > p; hence -ve charge is obtained.

Question 16. With the help of an activity in daily life, how can you prove that atoms are divisible. Answer:   Activity

• Take a scale, rub it on hair, try to attract a small bit of paper.
• Now divide the bit of paper further into smaller pieces.
• Again bring the charged scale near to this pieces of papers.
• You will observe that the bits of paper still get attracted.

Question 17. In the structure of an atom why are protons present in the centre and are not pulled outside by the electrons as both are oppositely charged with same unit of charge? Answer:  Protons are heavy with mass 1 unit and hence are concentrated in the centre of the atom. The mass of electrons is negligible i.e.1/1800 times less than that of protons. Hence are not able to attract the protons and pull them out of the nucleus, although their charge is of same value.

Question 18. According to you, among the structure of atom studied which model is correct and why? Answer:  Bohr’s model of an atom is the best model and is correct because it gives the explanation of nucleons (protons and neutrons) in the centre and how electrons revolve around the nucleons in their discrete, special orbits, so electrons don’t loose/radiate energy and remain bonded in their shell.

NCERT Solutions for Class 9 Science Chapter 4 Long Answer Type Questions

Question 1. Give an activity to understand the implications of Rutherford’s a scattering experiment by a gold foil. Answer:  To understand the implications of Rutherford’s a-particle scattering experiment: Activity: Let a child stand in front of a wall with his eyes closed. Let him throw stones at the wall from a distance. He will hear sound for each strike of stone on the wall. This is like a nucleus of the atom. But if a blind-folded child has to throw stones at a barbed-wire fence, most of the stones would not hit the fencing and no sound would be heard. This is because there are lots of gap in the fence which allows the stone to pass through them. This is like empty space in an atom through which a-particles will pass through. Based on the above activity and similar reasoning Rutherford concluded the a-particle scattering experiment as: (1) Most of the space inside the atom is empty as a-particles passed through the foil. (2) Very few particles deflected from their path, this show that positive charge occupies less space. (3) A very small fraction of a-particles are deflected by 180°, this shows that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.

Question 2. What are isotopes? State its characteristics, give uses of isotopes? Answer:  Atoms of same element with same atomic number but different mass number are isotopes. Characteristics:  (1) Physical properties of the isotopes are different e.g. mass, density. (2) Chemical properties of the isotopes are same due to same number of electrons. Uses: (1) Uranium isotope is used as a fuel in nuclear reactor (U-235). (2) Cobalt isotope is used for treatment of cancer (Co-60). (3) Iodine isotope is used in the treatment of goitre.

NCERT Solutions for Class 9 Science Chapter 4 Value-Based Questions

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 আসছালামু আলাইকুম প্রিয় নবম শ্রেণীর শিক্ষার্থী বন্ধুরা আজকে আমি এই পোস্টে তোমাদের নবম শ্রেণীর ৪র্থ সাপ্তাহের এসাইনমেন্ট সমাধান শেয়ার করবো। আসা করি তোমাদের উপকারে আসবে। 

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Class 9 Chemistry 4th Week Assignment Answer 2021

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' ক ' উচ্চ বিদ্যালয় 

ঢাকা । 

বিষয় : প্রত্যেক শিক্ষার্থীর রসায়ন পরীক্ষাগারে বিশেষ সতর্কতা অবলম্বন করা আবশ্যক সম্পর্কিত প্রতিবেদন । 

সূত্র / স্মারক নং : ঢা.উ.বি.২০২১-৩ 

তারিখ : ২৮ মার্চ , ২০২১ ।

জনাব , বিনীত নিবেদন এই যে , আপনার আদেশ নং ঢা.উ.বি.২০২১-৩ তারিখ : ২৮ মার্চ , ২০২১ অনুসারে “ প্রত্যেক শিক্ষার্থীর রসায়ন পরীক্ষাগারে বিশেষ সতর্কতা অবলম্বন করা আবশ্যক ” শীর্ষক প্রতিবেদনটি নিম্নে পেশ করছি । 

প্রত্যেক শিক্ষার্থীর রসায়ন পরীক্ষাগারে বিশেষ সতর্কতা অবলম্বন করা আবশ্যক যেখানে বিজ্ঞানের বিভিন্ন পরীক্ষা - নিরীক্ষা এবং গবেষণা করা হয় তাকে পরীক্ষাগার বা গবেষণাগার বলে ।

তাই যেখানে রসায়নের পরীক্ষা - নিরীক্ষা বা গবেষণা করা হয় তাকে রসায়ন পরীক্ষাগার বা রসায়ন গবেষণাগার বলে । রসায়ন গবেষণাগারে থাকবে বিভিন্ন রাসায়নিক দ্রব্য । প্রায় প্রত্যেকটি রাসায়নিক দ্রব্য আমাদের জন্য অথবা পরিবেশের জন্য কম / বেশি ক্ষতিকর । কোনাে রাসায়নিক দ্রব্য বিস্ফোরক জাতীয় , কোনাে রাসায়নিক দ্রব্য দাহ্য ( সহজেই যাতে আগুন ধরে যায় ) , কোনােটি আমাদের শরীরের সরাসরি ক্ষতি করে আবার কোনােটি পরিবেশের ক্ষতি করে । 

রসায়ন পরীক্ষাগারের যে যন্ত্রপাতি বা পাত্র ব্যবহার করা হয় তার বেশিরভাগই কাঁচের তৈরি । তাই এ রসায়ন পরীক্ষাগারে ঢােকা থেকে শুরু করে বের হওয়া পর্যন্ত প্রতিটি পদক্ষেপে সতর্কতামূলক ব্যবস্থা নিতে হবে । অসতর্ক হলেই যে কোন ধরনের দুর্ঘটনা ঘটে যেতে পারে । যেমন- এসিড গায়ে পড়লে শরীরের ক্ষত সৃষ্টি হবে , পােশাকে পড়লে পােশাকটি নষ্ট হয়ে যেতে পারে । এছাড়া রসায়ন গবেষণাগারে অগ্নিকাণ্ড বিস্ফোরণসহ নানা ধরনের ছােট বড় দুর্ঘটনা ঘটতে পারে । তাই শরীরকে রক্ষা করতে হলে নিরাপদ পােশাক বা অ্যাপ্রােন পরতে হবে ।

যে কোন রাসায়নিক দ্রব্য ব্যবহারের আগেই আমাদের জেনে নিতে হবে সে রাসায়নিক দ্রব্য টি কোন প্রকৃতির । আর সেটি বােঝানাের জন্য রাসায়নিক পদার্থের বােতল বা কৌটার লেভেলে এক ধরনের সাংকেতিক চিহ্ন ব্যবহার করা হয় । এ সংক্রান্ত একটি সার্বজনীন নিয়ম চালুর বিষয়কে সামনে রেখে জাতিসংঘের উদ্যোগে পরিবেশ ও উন্নয়ন নামে একটি সম্মেলন অনুষ্ঠিত হয় । এ সম্মেলনে বিভিন্ন পদার্থের ঝুঁকি এবং ঝুঁকির মাত্রা বুঝানাের জন্য সার্বজনীন সাংকেতিক চিহ্ন নির্ধারণ করা হয় ।

নিচে বিভিন্ন রাসায়নিক পদার্থের ঝুঁকি , ঝুঁকির মাত্রা ও সাবধানতা সম্পর্কে লেখা হলাে 

১. দাহ্য পদার্থ : প্রাকৃতিক গ্যাস ( জ্বালানি ) দাহ্য পদার্থ । এসব পদার্থের দ্রুত আগুন ধরে যেতে পারে । তাই এদের আগুন বা তাপ থেকে সবসময় দূরে রাখতে হবে । 

২. বিষাক্ত পদার্থ : বেনজিন , ন্যাপথালিন পদার্থ বিষাক্ত প্রকৃতির । তাই শরীরে লাগলে বা শ্বাস - প্রশ্বাসের মাধ্যমে শরীরে প্রবেশ করলে শরীরের নানা ধরনের ক্ষতি হয়ে যেতে পারে । এ ধরনের পদার্থ ব্যবহারের সময় অ্যাপ্রােন , হ্যান্ড গ্লাভস , সেফটি গগলস ইত্যাদি ব্যবহার করতে হবে ।

৩. স্বাস্থ্য ঝুঁকিপূর্ণ পদার্থ : এ পদার্থের উদাহরণ হলাে বেনজিন , টলুইন , জাইলিন । ইত্যাদি । এ ধরনের পদার্থ ত্বকে লাগলে বা শ্বাস - প্রশ্বাসের সাথে শরীরের ভেতরে গেলে শরীরের স্বল্পমেয়াদী বা দীর্ঘমেয়াদী ক্ষতিসাধন করে । এগুলাে শরীরের মধ্যে গেলে ক্যানসারের মতাে কঠিন রােগ হতে পারে কিংবা শ্বাসতন্ত্রের ক্ষতিসাধন করতে পারে । তাই এগুলােকে সতর্কভাবে রাখতে হবে এবং ব্যবহারের সময় অ্যাপ্রােন , হ্যান্ড গ্লাভস , সেফটি গগলস ইত্যাদি ব্যবহার করতে হবে ।

 ৪. পরিবেশের জন্য ক্ষতিকর : ভারি ধাতু ( লেড , মার্কারি , আর্সেনিক ) পরিবেশের জন্য ক্ষতিকর । অর্থাৎ এ ধরনের পদার্থগুলাে উদ্ভিদ ও প্রাণী উভয়ের জন্যই বিপজ্জনক ।

তাই এগুলােকে ব্যবহারের সময় যথেষ্ট সতর্ক হওয়া প্রয়ােজন । আবার , ব্যবহারের পরে যেখানে - সেখানে না ফেলে তা একটি নির্দিষ্ট স্থানে রাখতে হবে । এসব পদার্থকে যথাসম্ভব পুনরুদ্ধার করে আবার ব্যবহার করার চেষ্টা করতে হবে । তাহলে এগুলাে সহজে পরিবেশে ছড়িয়ে পড়তে পারবে না ।

 ৫. ক্ষত সৃষ্টিকারী : এ চিহ্নধারী পদার্থ শরীরে লাগলে শরীরে ক্ষত সৃষ্টি করে । শ্বাস প্রশ্বাসের সাথে গ্রহণ করলে তা শরীরের ভেতরের অঙ্গেরও ক্ষতিসাধন করতে পারে । হাইড্রোক্লোরিক এসিড , সালফিউরিক এসিড , সােডিয়াম হাইড্রোক্সাইডের গাঢ় দ্রবণ এ জাতীয় পদার্থের উদাহরণ ।

তাই , রসায়ন পরীক্ষাগারে ব্যবহৃত অ্যাপ্রােনের হাতা হবে হাতের কবজি পর্যন্ত । আর লম্বায় হাটুর নীচ পর্যন্ত । এটি সাদা রঙের হয়ে থাকে । হাতকে সুরক্ষার জন্য ব্যবহৃত হয় হ্যান্ড গ্লাভস , চোখকে রক্ষা করার জন্য সেফটি গগলস ব্যবহার করা হয় । রসায়নাগারে অবস্থানের সময় প্রত্যেক শিক্ষার্থীকে নিজের নিরাপত্তা রক্ষার ব্যাপারে সচেতন হতে হবে এবং যাবতীয় সচেতনতা অবলম্বন করতে হবে ।

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Class 9 Assignment Answer 2021 of All Subjects

4th Week Class 9 Assignment Answer 2021 For All Subjects. Welcome to our today’s intensive discussion and solution sharing session of the assignments for class 9. This will play an impeccable role in preparing your assignments far better than anyone who isn’t following our solutions. We will cover a wide range of subjects in this write-up, starting from Bangla and going all the way up to ICT.

This is the part of our ongoing answer sharing process for the assignments in different classes of secondary schools. As exams are postponed till date and there is no clear announcement about the retention of the exams, an assignment is the only alternative way of judging the merit of the students. Let us help you perform better in the assessment.

Class 9 Assignment Answer And Question

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Class 9 Assignment Syllabus

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Class 9 Bangla Assignment Answer

First things first, our creatively written solution to the Bangla assignment in class 9 for the first week is a gem. It will help you understand the topics in the syllabus better for preparing a better paper for assessment.

Download Answer

Click on the following image and download the solution to the Bangla assignment as soon as possible. Afterward, get back to your study and use this as a guide to complete your writings within the deadline. We have prepared these answers in a way that you will get the best outcome with less hard work.

Class 9 Chemistry Assignment Answer

Answer here: প্রত্যেক শিক্ষার্থীর রসায়ন পরীক্ষাগারে বিশেষ সর্তকতা অবলম্বন করা আবশ্যক

Class 9 Business Entrepreneurship Assignment Answer

• ৯ম শ্রেণি ব্যবসায় উদ্যোগ ৪র্থ সপ্তাহের এ্যাসাইনমেন্ট
• ”পরিবেশ বাঁচলে বাঁচবে পৃথিবী” – অনধিক ৩০০ শব্দের মধ্যে একটি প্রতিবেদন লিখ।

Class 9 English Assignment Answer

Secondly, we have the solution to the English assignment for the students of class 9 who need to study a lot on various topics. From the comprehensive writing to the grammar part, you need to know every small detail to perform the best in exams.

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Class 9 Math Assignment Answer

Keeping all the difficulties of different topics in math for class 9, we have organized an easy-to-understand solution to all the questions required for this week. You will find this solution extremely helpful to complete your assignment on time.

This solution has been reviewed by experienced teachers to make it error-free and understandable by students having any level of merit. What you need to do is click on the image and download it. Go through the solution to understand the topics better and then make your own assignment shine. Simple as that.

Class 9 Science Assignment Answer

While we are going down the lane, our next stop is the solution to the science assignment of this week for class 9. But we assure you this isn’t the only solution for this subject. We will continue to update you on the latest solutions coming every week from now on.

For now, you should click on the image and download it for preparing your science assignment much better than anyone else. You can also share it with your friends if you feel it appropriate. We recommend sharing the solution as knowledge increases through sharing.

Class 9 Physics Assignment Answer

With a lot of tricky topics, physics is considered one of the toughest subjects for this assignment series by the students. To ease the topics to reach your level, we have arranged a solution prepared by some of the most experienced teachers in this subject.

Click on the following image to download the solution to the physics assignment for class 9 this week. This isn’t the end as we will continue to upload solutions for this subject in the successive weeks so that you don’t face any difficulty at that time too.

Class 9 ICT Assignment Answer

The last subject on this list of solutions is ICT, which students seem to have the least grip on. To fight the difficulties that arise in this subject we have prepared an extensive solution to the ICT assignment for class 9 that is presented here for your easy access.

Click on the following image and download the solution to the ICT assignment to not only make your answers look better but also clear your conceptions about all the smaller details in the syllabus. Expect us to upload the next solutions too so that you don’t get disappointed by facing the same type of difficulties in the next week.

Final Verdict

We are done for today as everything is probably in your hand now. This will only be a happy ending when you have downloaded all the solutions and made the best use of them. We hope for a great assessment and a successful future for you. Thank U For Getting in Touch With Class 9 Assignment Answer 2021.

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9 Class Chemistry Assignment Solution 2022 PDF file – 5th Week

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Class 9 Chemistry 4th Week Assignment Cover Page 2021

The 4th-week assignment for students of class 9 of Bangladesh has been published on 24 May 2021. Assignment from Chemistry for students who to Science in class 9. Students have to submit the assignment by following guidelines of authority. They have to attach a cover page with their soft assignment paper before submitting it. 

Assignment Cover Page 2021

How Tu make an assignment beautiful and get the highest mark in evaluation students and project makers to use? Use a beautiful page as a cover of their assignment. The cover page made an assignment looking nice. Authority or project in-charge marked the students good Refuse a beautiful cover with his assigned task. 

Class 9 Assignment Cover Page Design

An Assignment cover page is The immediate page that students can see right after the cover page is known as a front page. The cover page is also called a title page. It is as important as the cover page. Students can submit an assignment without a cover page; however, Students can never skip the front assignment page.

We have designed some awesome cover pages for students of class 9. You can use this cover page completely free to make your assignment beautiful and meaningful.

4th-week Assignment Cover Page Design for Class 9 Chemistry 

Are you looking for a cover page for the assignment of class 9 Chemistry?  yes, you are in the right place. There is An awesome cover page for class 9 Chemistry of assignment 2021. 

Students of class 9 need to submit their assignments to help attach the cover page. It helps the teacher or mentor to evaluate your assignment very easily. If you are skipped the attached and assignment cover page, it will be very difficult to examine your assignment property. However, the teacher may fall it very difficult to identify the owner of the assignment.

  Download 4th Week Chemistry Assignment Cover Page

There is three format Assignment cover page of class 9 Chemistry for 4th-week assignment. Click the expected download button below to get the assignment cover page completely free. You can edit and manage this assignment cover page with Microsoft Word or Photoshop.

• একটি নমূনা উত্তর দেখুন:  প্রত্যেক শিক্ষার্থীর রসায়ন পরীক্ষাগারে বিশেষ সর্তকতা অবলম্বন করা আবশ্যক

নবম শ্রেণির ৪র্থ এ্যাসাইনমেন্ট প্রশ্ন ও বাছাইকরা নমূনা উত্তর দেখুন

Assignment cover page design:

If you want to save time for writing assignments, you can use these readymade templates. Cover Pages will dramatically save your time. There is all subject assignments Cover page template available for class 9 also other classes. 

Design assignment cover pages are most editable in Microsoft Word and also Adobe Photoshop. These are very easy-to-use drag and drop systems.  You can just put your name on the textbox And printed it after save.

Click Here to get  4th Week Assignment and Answer for Class 6, 7, 8, and 9 by dshe.gov.bd

  Join the  BanglaNotice Facebook group  and  Download BanglaNotice Android App  to find weekly assignment updates.

You May Like:  Student Unique ID Form 2021 for School, College, Madrasha Class 6 to 12

Posted by Ansar Ahammad Bhuiyan

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