Question

What are ISOTOPES and ISOBARS?

Answer 1

Isobars are atoms of different elements having the same mass number but different atomic numbers.
Isotopes are nuclei having the same number of protons, but different numbers of neutrons, hence different mass number.

Answer 2

ISOTOPES ⇒ The atoms which have same atomic number but different mass                         number are known as isotopes.

For example = hydrogen has three atomic species, protium , deuterium and                        tritium.

ISOBARS ⇒  Atoms of those elements which have the same mass number                        but different atomic number, are called isobars.

For example = calcium atomic number 20 and argon atomic number 18. but he mass number of both these elements is 40.