Atoms And Molecules Class 9

Science Questions For atoms and molecules
on 22 Jan 2019, 10:30AM
  • Atomic Mass Unit
  • Atomic Masses
  • Dalton's Atomic Theory
Atoms And Molecules Questions..Download PDF

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1Match the following

Law/Theory Scientist
a. Law of conservation of mass 1. Proust
b. Atomic theory 2. Avogadro
c. Law of constant proportion 3. Lavoisier
d. a mole of a substance 4. Dalton

      A    B    C    D
a)  1     2     3     4
b)  4     3     2     1
c)  3     4     1     2
d)  3     1     2     4

2The fundamental particles that composed on the atom are-

a) Proton, electron, deuteron
b) Proton, electron, meson
c) Proton, electron, neutron
d) Proton, electron, photon

3 The size of the nucleus is measured in:

a) Fermi
b) amu
c) angstrom
d) cm

4The radius of an atomic nucleus is of the order of

a) 10⁻¹⁰ cm
b) 10⁻¹³ cm
c) 10⁻¹⁵ cm
d) 10⁻⁸ cm

5The Atomic theory of matter was given by

a) Dalton
b) Newton
c) Pascal
d) Avogadro

6 The nucleus of an atom consists of.

a) Proton and Neutron
b) Proton
c) Neutron
d) Electron, Proton, and Neutron

7 Atomic size is of the order of-

a) 10⁻¹³ cm
b) 10⁻¹⁰ cm
c) 10⁻⁸ cm
d) 10⁻¹⁵ cm

8 According to Rutherford’s atomic model, the electron inside an atom is-

a) Non-stationary
b) Stationary
c) Centralized
d) None of these

9 Electrons in the highest energy level of an atom are called_______.

a) Valence protons
b) Valence electrons
c) Orbital protons
d) Valence electrons

10 Which of the following has maximum Mass?

a) Electron
b) Neutron
c) Proton
d) Nucleus of Hydrogen

Most important

11 Rutherford’s α-scattering experiment related to the size of the-

a) Atom
b) Electron
c) Nucleus
d) Neutron

12 Which of the following has maximum Mass?

a) Electron
b) Proton
c) Neutron
d) Nucleus of Hydrogen

13 Who is awarded by Noble prize for the discovery of neutron?

a)Neil Bohr
b) Rutherford
c) Chadwick
d) Roentgen

14Which of the following particle is negatively charged?

a) proton
b) Neutron
c) Electron
d) Positron

15Electron move around the nucleus in

a) Translatory
b) Spin
c) Orbital
d) Vibrational

16The subatomic particle that does not have an electric charge is a/an____.

a) Electron
b) Proton
c) Neutron
d) All options are correct.

17How is the atomic mass number determined?

a) By total number of protons
b) By adding number of
protons and neutrons

c) By total number of neutrons
d) By total number of electrons

18Calculate the molecular mass of HNO3

a) 36μ
b) 16 μ
c) 63 μ
d) 30 μ

19Which of the following has the highest molecular mass?

a) H₂O
b) O₂
c) CO₂

20 The atomic mass unit should be equal to the ____The mass of a carbon-12 atom

a) 1/6
b) 1/12
c) 1/4
d) 1/2

21Al₂ (SO₄)₃ is a compound, the ions present in it are ------

a) AL²⁺, SO₄³⁻
b) Al³⁺ SO₄²⁻
c) AL²⁻ SO₄³⁺
d) Al³⁻ SO₄³⁺


22 What are the components of a nucleus of an atom?

a) Only Protons
b) Only Neutrons
c) Neutrons and Electrons
d) Protons and Neutrons

23 Which of the following isotope to find blood clot?

a) U-235
b) Na-24
c) Co-60
d) I-131

24 What is the mass of one mole of a substance in grams is called?

a) Molecular Mass
b) Atomic mass
c) Mass No./
d) Nuclear mass /

25 Which of the following scientist suggested that symbols of elements can be made by first one or two letters of the name of elements.

a) Berzelius
b) Dalton
c) Rutherford
d) Lavoisier

26 Which of the following molecule of an element is known as tetratomic

a) P₄
b) O₃
c) O₂
d) CH₄

27 Total number of atoms present in two molecules of water

a) 6
b) 5
c) 4
d) 8

28 Latin name of sodium

a) Kalium
b) Natrium
c) Cuprum
d) Stannum/

29 If Na has 11 electrons then how many electrons will be there in Na+

a) 12
b) 11
c) 10
d) 15

30Latin name of Gold

a) Argentum
b) Aurum
c) Hydragyrum
d) Ferrum

31If chlorine(Cl) has 17 electrons, then how many electrons will be there in Cl

a) 16
b) 18
c) 17
d) 20

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