NIOS Class 10 Science & Technology Chapter 5 Solution

NIOS Class 10 Science & Technology Chapter 5 Solution – Atomic Structure

NIOS Class 10 Science & Technology Solution Chapter 5 Measurement in Science and Technology. NIOS Class 10 Science & Technology Chapter 5 Question Answers Download PDF. NIOS Class 10 Science Notes.

NIOS Class 10 Science & Technology Chapter 5 Solution

Board NIOS
Class 10th  (Secondary)
Subject Science and Technology (212)
Topic Question Answer, Solution, Notes

 

CHAPTER: – 5. (ATOMIC STRUCTURE)

 

INTEXT QUESTIONS 5.1

1) Name two charged particles which constitute all matter.

Ans: – The charged particles present in matter is electron and proton.

 

2) Describe a cathode ray tube.

Ans: – In cathode ray tube there are two metal electrodes in an evacuated glass tube. The negatively charged electrode is called cathode and positively charged electrode known as anode. These electrodes came from high voltage source.

 

3) Name the negatively charged particles emitted from the cathode in the cathode ray tube?

Ans: – The negatively charged particles emitted from the cathode ray tube is electron.

 

4)what do the canal rays obtained by using different gases have different e/m values?

Ans: – Electrons emitted from the cathode collide with the neutral atoms ofthe gas present in the tube, and because of these one or more electrons present in them which laves behind positive charged particles. This travel towards the cathode because the atoms have different number of protons present
So, it gives positively charged ions with different e/m values.

 

INTEXT QUESTIONS 5.2

1) Describe Thomson’s model of atom. What is it called?

Ans: – Thomson’s model states that a large sphere of uniform positive charge with a number of small negatively charged electrons scattered around this outer surface.
This model was called as plum pudding model.

 

2) What would have been observed in the α-ray scattering experiment if the Thomson’s model was correct?

Ans: – If the Thomson’s model was correct because of which we will see that most of the α- particles in the α-ray scattering experiments passes through the atom in that.

 

3) Who performed the α-ray scattering experiment and what were the observations?

Ans: – The α-ray scattering experiment tells us that a stream of α-particles from a radioactive source was directed to a thin pieceof gold foil and after that we see that most of the α-particles passed straight through the gold foil butsomeof α-particles deflected also and a few particles by large angles, and very few experienced a rebound as well.

 

4)Describe the model of atom proposed by Rutherford.

Ans:- Rutherford’s model described that the atom contains a dense and positively charged region called nucleus at its centre whereas negatively charged electrons move around it but positive charge, most of the mass of atom is in nucleus too.

 

INTEXT QUESTIONS 5.3

1) Give any two drawbacks of Rutherford’s model of atom.

Ans: – The drawback of Rutherford’s model that it doesn’t explain the stability of the atom and the second is the distribution of electrons as well as relationship between the atomic mass and atomic number.

 

2)State the postulates of Bohr’s model.

Ans: – The Bohr’s model postulate is,

I. The electrons move in circular paths around central nucleus.

II. The electron changes energy level by absorbing or releasing energy.

 

3) How does Bohr model of an atom explain the stability of the atom?

Ans: – The Bohr’s model described through the stability as the electrondoes not lose energy if it presents in a fixed energy level.

INTEXT QUESTIONS 5.4

1) What is a neutron and where is it located in the atom?

Ans: – The difference between the proton and electron number of an atom is known as neutron which is located inside the atom nucleus.

 

2)How many neutrons are present in the α-particle?

Ans: – There are two neutrons in an alpha particle.

 

3)How will you distinguish between an electron and a proton?

Ans: – The proton are the positive charged particles whereas the electron is the negatively charged particles.

 

INTEXT QUESTIONS 5.5

 

1) A sodium atom has an atomic number of 11 and a mass number of 23. Calculate the number of protons, electrons and neutrons in a sodium atom.

Ans: – As the atomic number denotes the proton number so the number of protons is 11 in sodium. No of electron is 11 and the number of neutrons is (23 – 11=12) 12.

 

2) What is the mass number of an atom which has 7 protons and 8 neutrons?

Ans: – Mass number = number of protons + number of neutrons.
Or, mass number = 7 + 8 =15.

 

3)Calculate the number of electrons, protons and neutrons in 40Ar18and 49K19.

Ans: – In 40Ar19 the number of electron and proton is 18 and the number of neutrons is (40-18=22) 22.

In 49K19 the number of electron and proton is 19 and the number of neutronsis(49 – 19=30) 30.

 

INTEXT QUESTIONS 5.6

1) How many shells are occupied in the nitrogen (atomic number =7) atom?

Ans: – The electron configuration of any element tells us about the number of shells inside it. As from the electronic configuration we know that its 2,5 so it will occupy 2 shells.

 

2) Name the element which has completely filled first shell.

Ans: – From the electronic configuration of Helium we say that it has filled first shell.

 

3) Write the electronic configuration of an element having atomic number equal to 11.

Ans: – The electronic configuration of elements having the atomic number 11 is 2,8,1.

 

TERMINAL EXERCISE

1)How did J.J. Thomson discover the electron? Explain his “plum pudding” modelof the atom.
Ans: – This theorem plum pudding discovered by j j Thomson; it is discovered while electron are passes through the cathode ray tube. The negatively charged electron are the main reason for this.

 

2) What made Thomson conclude that all atoms must contain electrons ?

Ans: – Thomson’s model states that a large sphere of uniform positive charge with a number of small negatively charged electrons scattered around this outer surface. This model was called as plum pudding model.

 

3) Identify the following subatomic particles:

(a) The number of these in the nucleus is equal to the atomic number.
Ans: – Proton has the same number as the atomic number.

 

(b) The particle that is not found in the nucleus.
Ans: – Electrons are not found in nucleus of an atom.

 

(c) The particle that has no electrical charge.
Ans: – Neutron has no electrical charges on it.

(d) The particle that has a much lower mass than the others subatomic particles.
Ans: – Electron has a much lower mass than the others subatomic particle.

 

4)Which of the following are usually found in the nucleus of an atom?

(a) Protons and neutrons only

(b) Protons, neutrons and electrons

(c) Neutrons only

(d) Electrons and neutrons only.

Ans: – Option (a).

 

5) Ernest Rutherford’s experiment with alpha particles and gold foil. How did this lead to the discovery of the nucleus?

Ans: – In a Rutherford experiment we see that there is gold foil and the alpha particles strike in that with a certain speed and after that we see that the some of particles comes back, some passes through it so we came to this conclusion that there presents a certain thing in centre which restricted the flow so we say that it is the nucleus of atom.

 

6)What does the atomic number tell us about an atom?

Ans: – The atomic number tells us about the number of protonsin that molecule.

 

7) What is the relationship between the numbers of electrons and protons in an atom?

Ans: – The number of electron(E) and the number of proton(Z) are relatable by the relation A=Z.

 

8) How did Neil’s Bohr revise Rutherford’s atomic model?
Ans: – The Neil’s Bhor states that in an atomic model there are different energy levels in that and an electron release some energy when it travels from the upper to lower levels and gain or needed some energy when it travels lower to upper energy levels.

 

9) What is understood by a stationary state ?

Ans: – There are different state in a matter as when it gets excited at that time this state is called quantize states and this quantize stat is know as the stationary states.

 

10) What is a shell? How many electrons can be accommodated in L-shell?

Ans: – In a shell this represent the maximum number of electrons that can be kept in it. And this number of electrons is denoted by electronic configuration.

The Maximum capacity of L shell is 8.

 

11) State the rules for writing the electronic configuration of elements.

Ans: – The electronic configuration of an element is states that about the different energy levels of that element. And are rules that the electron first get in the K shell and then passes to the other shell in order of K>L>M…..

Updated: February 21, 2022 — 11:02 am

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