atomic structure molecules and nuclear chemistry - Category wise Question and Answer Practice Test with Solutions

Question : 11 [BPSC (Pre) 1999]

What is the mass number of an element, the atom of which contains two protons, two neutrons and two electrons?

a) 4

b) 6

c) 2

d) 8

Question : 12 [MPPCS (Pre) 2005]

Which of the following is not a part of an atom?

a) Proton

b) Neutron

c) Electron

d) Photon

Question : 13

The chemical symbol for barium is

a) Ba

b) Be

c) B

d) Bi

Question : 14

The molecular formula P₂O₅ means that

a) the ratio of the mass of P to the mass of O in the molecule is 2:5

b) there are twice as many P atoms in the molecule as there are O atoms

c) a molecule contains 2 atoms of P and 5 atoms of O

d) the ratio of the mass of P to the mass of O in the molecule is 5 : 2

Question : 15 [NDA]

Which of the following pairs is/are correctly matched?

1. Isotopes : Atoms with same atomic number but different atomic mass
2. Isobars : Atoms with same number of neutrons but different atomic number
3. Isotones : Atoms with same mass number but different atomic number

a) 1 and 2 only

b) 1 only

c) 1, 2 and 3

d) 2 only