Given the balanced equation representing a reaction:
mg(s) + ni2+(aq) ==> mg2+(aq) + ni(s)
what is the total number of moles of electrons lost by mg(s) when 2.0 moles of electrons are gained by ni2+(aq)?
(1) 1.0 mol (3) 3.0 mol
(2) 2.0 mol (4) 4.0 mol

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.