S) The elements with some atomic number but different
mass is called

The elements with the same atomic number but different  mass are called isotopes.

Explanation:

Isotopes are atoms of the same element that differ in the number of neutrons in their nuclei. That is, isotopes are atoms that have the same atomic number - equal numbers of protons - but different atomic mass - different number of neutrons. Their chemical properties, however, do not differ.

according to hess's theory, when the magma cooled, it would expand and push the tectonic plates apart. it would push the north and south america plates to the west and eurasia and africa ones to the east. the atlantic ocean would get wider but the coastlines of the masses would stay the same.

harry hammond hess was a geologist and a united states navy officer in the second world war. he is considered to be one of the founding fathers of the theory of plate tectonics. he is known for his theories on sea floor spreading, stating that the movement of the continents was the result of see floor spreading. the continents are attached to the plates and do not move separately. the plates themselves shift and change shape, carrying the continents along.