Question

why is it that atomic number is more important than atomic masses is predicting the chemical priodicity of elements

Answer 1

Atomic no. determines the no. if protons and electrons present in an atom, and is extremely useful in determining the characteristic of the element as well.

For example, by atomic no. we get the information about the possible oxidation states of the atom, wheher the atom will show ionic character or covalent character, whether it will be reactive or not, and is also used in various intricate measurements like atomic radius, kinetic energy of different energy levels and so on...

On the other hand, atomic mass varies greatly on moving down the period as we approach the radioactive series. So it's not much useful at that point in predicting anything.

Answer 2

Answer:

Atomic number is number of proton in an atom and during a chemical reaction in number of proton remain unchanged. Atomic number also gives number of electron present in Shell which participate in chemical reaction and decide chemical properties. Whereas atomic weight is the sum of number of proton and number of neutron atomic number. Thus atomic number is more important than atomic weight in predicting chemical properties of element.