What did henry moseley determine that contributed to understanding the atom?

Henry Moseley is a Physicist. He used x-rays and discovered the atomic number of each element, that led to more accurate organization of the periodic table.

He arranged the elements in the periodic table by the number of protons of the elements not on the basis of atomic weights of the elements.

This disappeared the the flaws in the periodic table that had been making scientists uncomfortable.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

the answer is c

tell me if wrong