20 POINTS PLEASE ANSWER

What trend does the first ionization energy follow in the periodic table?

a it increases when going down a group

b it decreases when going across a family

c it decreases when gpoing down a group

d it stays the same within a family

PLEASE ANSWER I CANT FIGURE THIS ONE OUT

ITS C I GOT IT RIGHT NVM

c. It decreases when going down a group.  

Explanation:

Ionization energy is the energy needed to remove an electron from the neutral gaseous atom.

It is represented in kJ/mol.

As we move down the group the ionization energy decreases, since the outermost electrons are far away from the nucleus of an atom and so attains greater shielding effect. They encounter a weaker force of attraction to the +ve charge on the nucleus. And so, Ionization energy decreases from top to bottom in a group.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)