Question

What are isobars? Give one example.

Answer 1

Isobars:
The atoms of different elements which have the same mass number $A$, but different atomic number $Z$, are called isobars.
${}_8^{18}O$ and ${}_9^{18}F$ are isobars.
Oxygen atom has atomic number $8$ and mass number $18$. Fluorine atom has atomic number $9$ and mass number $18$. These are different elements having the same mass number.