Describe the relationship between the number of valence electrons and the chemical properties of atoms.

The valence electrons are determined by the column that the element falls in.  

Column 1 has 1 valence electron  

Column 2 has 2 valence electrons  

Column 13 has 3 valence electrons  

Column 15 has 5 valence electrons  

column 16 has 6 valence electrons  

column 17 has 7 valence electrons  

Elements are trying to become stable by filling the outer energy level. Columns 1,2,3 do this by losing 1,2 or 3 electrons and becoming positive ions. +1, +2, +3, respectively  

Columns 15, 16, 17 do this by taking those electrons and becoming negative ions. -3, -2, -3. respectively.

the answer to this question is 3.

the correct answer is:

a. formation of precipitation