How do I find the mass of MgO2 in grams?

56.303g

Explanation: Look on the periodic table and add up the atomic masses.

Mg: 24.305g

O: 15.999g

24.305 + 15.999 + 15.999 = 56.303g

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72