Chemistry For Class IX (New Book ) - Chapter No. 2- Atomic Structure - Multiple Choice Questions And Fill In The Blanks

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Chapter No.2 - Atomic Structure
MCQs And Fill In The Blanks
Text Book Exercise

SECTION- A: MULTIPLE CHOICE QUESTIONS
Tick Mark (✓) the correct answer

1. In an atom number of protons and neutrons are added to obtain:
(a) number of electrons
(b) number of nucleons ✓
(c) atomic number of element
(d) number of isotopes

2. If proton number is 19, electron configuration will be:
(a) 2, 8, 9
(b) 2, 8, 8, 1 ✓
(c) 2, 8, 1
(d) 2, 8, 3

3. If nucleon number of potassium is 39, number of neutrons will be:
(a) 39
(b) 19
(c) 20 ✓
(d) 29

4. The isotope C-12 is present in abundance of:
(a) 96.9%
(b) 97.6%
(c) 98.8% ✓
(d) 99.7%

5. Electronic configuration is distribution of:
(a) proton
(b) neutron
(c) electron ✓
(d) positron

6. Which one of the following is most penetrating?
(a) electron
(b) Proton
(c) alpha particle
(d) neutron ✓

7. How many sub-shells in a L shell:
(a) one
(b) two ✓
(c) three
(d) four

8. De Brog extend the wave particle duality to electron in:
(a) 1920
(b) 1922
(c) 1923 ✓
(d) 1925

9. Name the material of screen which used in Rutherford atomic model:
(a) Aluminum foil
(b) Zinc sulphide ✓
(c) Sodium sulphide
(d) Aluminum sulphide

10. Which rays are used for sterilization of medical instruments:
(a) α-rays
(b) β-rays
(c) γ-rays ✓
(d) x-rays

Fill In The Blanks:

1. The Electron is lightest particle carrying a negative charge in an Atom discovered by J.J.Thomson and William Crooks.
2. The Proton is positively charge particle discovered by Goldstein in 1886.
3. J.J.Thomson investigate properties of proton in 1897.
4. In 1932 Chadwick become successful to discover Neutron.
5. Lord Rutherford in 1911, carried out series of experiments and proposed a new model for the atom
6. Lord Rutherford in 1911, discovered that an atom contains nucleus at the center and electrons revolve around this nucleus.
7. In 1913 Neil Bohr proposed another atomic model to remove or replaced the Rutherford atomic model.
8. In 1913 Neil Bohr explained the line spectrum of Hydrogen atom based on quantum theory of Max Planck.
9. In 1923 Lois De Broglie extend the wave particle duality to electron.
10. In 1923 Lois De Broglie proposed a hypothesis that all matter has particle as well as wave nature at the sub microscopic level.
11. The Energy levels or Shell or Orbital are all possible paths on which electrons are revolving around nucleus.
12. The Energy levels or Shell or Orbital are shows by 'n'.
13. The Energy levels or Shell or Orbital are named as K, L, M, N, O, P.
14. Main energy level are divided in to sub energy levels and known as sub shells.
15. The distribution of electrons among the different orbits/shells and sub shells is known as the electronic configuration of an atom.
16. Atoms of the same elements having same atomic number but different atomic masses are called isotopes.
17. Isotopes have same number of electron and same number of protons, but different number of neutrons.
18. The Isotopes are used in research laboratories, medical centers, industrial facilities, food irradiation plants and many consumer products.