Answer : The correct option is, forms of the same element that differ in the number of neutrons in each atom
Explanation :
Isotopes : It is defined as the forms of same element that have the same number of protons and electrons but differ in the number of neutrons.
For example : Carbon-12, carbon-13 and carbon-14 is an isotopes due to the same number of protons and electrons and different number of neutrons.
Carbon-12
Atomic number = 6
Atomic mass = 12
Atomic number = Number of protons = Number of electrons = 6
Number of neutrons = Atomic mass - Atomic number = 12 - 6 = 6
Carbon-13
Atomic number = 6
Atomic mass = 13
Atomic number = Number of protons = Number of electrons = 6
Number of neutrons = Atomic mass - Atomic number = 13 - 6 = 7
Carbon-14
Atomic number = 6
Atomic mass = 14
Atomic number = Number of protons = Number of electrons = 6
Number of neutrons = Atomic mass - Atomic number = 14 - 6 = 8
