Question

What do we call the atoms of the same atomic number and different mass numbers
A. Isobars
B. Isomers
C. Isotones
D. Isotopes

Answer 1

Hint: Isotopes are those atoms which have different neutron numbers or nucleon numbers. The elements which have the same protons and have different neutrons are called isotopes of the given element.

Complete step by step answer:
Isobars: Isobars can be defined as the atoms which have the same number of nucleons. They have different atomic numbers but have the same atomic mass. Argon, calcium and potassium are isobars as they have the same atomic mass.
Isomers: The atoms which have the same atomic number of each element then they are said to be isomers. It is necessary that they have the same physical and chemical properties. The arrangements of atoms in space are different.
Isotones: The elements are said to be isotones if they have the same number of neutrons but have different numbers of protons. Carbon – 13 and boron – 12 have the same number of neutrons which is 7 so, they are isotones.
Isotopes: The isotope is defined as the variants which have the same number of protons. They have different numbers of neutrons in each atom of the given element. Carbon-12, Carbon-13, and Carbon-14 have atomic mass 12, 13 and 14 respectively, these are the isotopes of carbon.
Hence, from the explanation we finally got that the atoms having the same number of atoms but having different atomic masses are called Isotopes.

So, the correct answer is Option D .

Note:
Due to the presence of different numbers of electrons, protons and neutrons isotopes and isobars have different properties. There are both the same chemical and physical properties in isotopes whereas in isobars, they have the same physical properties only.