Question

What is the relationship between two elements X and Y whose atomic number is 18 and 20 respectively, but their mass numbers remain same as 40?​

Answer 1

The elements are Isobars.

Step-by-step explanation:

• If two elements have different atomic numbers, but same atomic mass they are called isobars.
• Here,X and Y have atomic number 18 and 20 ,but have the same atomic mass .So, they are clearly isobars.
• They have differing atomic numbers because the no. of protons in each element is different.
• But,they end up having the same atomic mass because they have enough neutrons to equate the sum total of nucleons between them.
• Isobars are present in different regions of the periodic table.