The total number of protons and neutrons present in atom is called

_____ is spherical and most of the space in its empty.

____ is considered to be a divisible particle.

Atoms having same mass number but different atomic number is known as

Atoms of one element can be changed into atoms of other elements by

The atomic mass of an element is expressed in grams, is known as

_______ is the volume occupied by one mole of any gas at STP.

The word atom is derived from the Greek word

A _______ is the smallest particle of an element or compound.

Neutron was discovered by