Complete the three words. The oxidation state tells you how many electrons an atom has g , l , or s , in forming a compound.

Gained, Lost , Shared

Explanation:

The oxidation state tells you how many electrons an atom has GAINED , LOST , or SHARED , in forming a compound.

Oxidation state is defined as the  the total number of electrons that an atom gains or loses when forming a chemical bond with another atom.

To form an ionic bond for example in NaCl, Na, with 11 electrons and one valence electron in its outermost shell donates or lose that valence electron to Chlorine  with 17 electron and 7 in its outermost shell. Therefore Sodium, Na acquires the +1 oxidaton state to become stable and Chlorine acquires the -1 oxidation state  to become stable  forming the  NaCl compound.

To form a covalent compound, There must be sharing of electrons between atoms.For example, in PCl3,  The  phosphorous atom with atomic number 15 shares its three unpaired electrons with the single valence electrons of three chlorine atoms. making the four molecules to attain stability with  Phosphorous having +3 and the chlorine atoms having -1 oxidation states

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.