Page 3 - 3.HOME ASSIGNMENT-CONCEPT MAP

(c) Alpha particles are composed of electrons.
(d) If an iron foil was used then almost all the alpha particles would
have bounced back.

Q6 According to Rutherford the electrons do not lose energy during their 1
revolution around the nucleus of an atom.

Concept: Bohr’s model of an atom
Q1. Assertion: In Bohr’s model of an atom the electrons cannot jump from 1
one orbit to another.
Reason: Bohr’s orbits are stationery orbits.
Q2 Assertion: Neutrons are charged particles. 1
Reason: Neutrons are present inside the nucleus of an atom.
Q3 Assertion: Electrons radiate energy when jump from one orbit to other. 1
Reason: Bohr’s model could not explain the model of Hydrogen atom.
Q4 Which of the following was not there in Bhor’s model of an atom? 1

(a) Electrons revolve in discrete orbits.
(b) During revolution the electrons lose energy.
(c) Electrons can jump from one orbit to another.
(d) Electrons do not collide with the nucleus.

Q5 Neutron were discovered by: 1

(a) James Chadwick
(b) E. Goldstein
(c) J.J. Thomson
(d) Rutherford

Q6 Electrons revolve around the nucleus in …………… orbits without 1
emission of ………………

Concept: Atomic number and mass number, Bohr Burry scheme
and distribution of electrons

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Q1. Assertion:17Cl and 17Cl are have same number of protons. 1
Reason: The atomic number of an element is equal to the number of
electrons present in atom of it.
Q2 Assertion: L shell can accommodate maximum 8 electrons. 1
Reason: The outermost shell of an atom can accommodate maximum 8
electrons.
Q3 Assertion: Mass number of calcium is 40. 1
Reason: Calcium atom has 20 protons and 20 electrons.
Q4 Which of the following is the correct electronic configuration of sodium atom 1
(11Na )
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(a) K=2,L=2,M=7
(b) K=2,L=8,M=1
(c) K=2,L=1,M=8
(d) K=2,L=5,M=5