Question

The atomic number of Calcium and Argon are $20$ and $18$ respectively, but the mass number of both these elements is $40$. What is the name given to such a pair of elements?

Answer 1

• The atomic number of an atom is determined by counting all the protons in its nucleus.
• All the atoms of a specific element have the same amount of protons, and as a result, have the same atomic number, which is symbolized by the letter “Z.”
• The mass of an atom is determined by the sum of the protons and neutrons. The nucleus of an atom is made up of protons and neutrons, which are collectively referred to as nucleons. It is symbolized by the letter "A."

Isobars:

• Isobars are elements that share the same mass numbers but have different atomic numbers. Isobars include Argon and Calcium.
• Examples: ${}_{18}{}^{}\mathrm{Ar}^{40},{}_{20}{}^{}\mathrm{Ca}^{40}$.