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

Question : 21

The isotopes of an element have

a) same atomic number

b) same mass number

c) same number of neutrons

d) None of these

Question : 22 [PCS (Pre) 2003]

In atom, neutron was discovered by

a) Chadwick

b) Rutherford

c) J.J. Thomson

d) Newton

Question : 23 [UPPCS (Mains) 2009]

The atoms, in which the number of protons is same but the number of neutrons is different, are known as

a) Isomers

b) Isotones

c) Isobars

d) Isotopes

Question : 24

Which one of the following statement is not true ?

a) The total number of neutrons and protons is always equal in a neutral atom

b) The total number of electrons and protons in an atom is always equal

c) Most of the space in an atom is empty

d) The total number of electrons in any energy level can be calculated by the formula 2n²

Question : 25 [NDA]

In which one of the following is the valence electronic configuration, ns²np³ found ?

a) Nitrogen

b) Oxygen

c) Carbon

d) Argon