General Knowledge - Physics - Discussion

@Bob Ajiboy

The mass number of chlorine (35.5) has been calculated from its isotopes only. so how can you take more isotopes. Also, the number of protons can never be a decimal.

Since, proton + neutron = Nucleus (mass number).

Let's consider the isotopes of chlorine.

The nucleus of the element exists to be either 37.5 or 35.5.

For isotope 37.5, the number of proton and neutron are 17.5 and 20 respectively and for isotope 35.5, a proton is 17.5 and the neutron changes to be 18.

Isotopes usually have the same number of protons and electrons.

Isotope - same atomic number.

Isobar - same mass number.

Isotones - same number of neutrons.

ISOTOPES are atoms of the same element having the same atomic number(Z) but different mass number(A).Examples as follows,
1 2 3
H H H
1 1 1

ISOBARS are atoms of different elements having the same mass number but different atomic number. Ex:
16 16
O N
8 7

ISOTONES are atoms of different elements having the same number of neutrons. Ex:

14 16
C O
6 8

What is Isotopes?