Determine the volume (liters) of 0.750 m naoh solution required to neutralize 1.50 l of 0.500 m h2so4. the neutralization reaction is: h2so4 (aq) + 2naoh (aq) → na2so4 (aq) + 2 h2o (l)

The balanced equation for the neutralisation reaction is as follows
2NaOH + H₂SO₄ --> Na₂SO₄  + 2H₂O
stoichiometry of NaOH to H₂SO₄ is 2:1
number of H₂SO₄ moles reacted - 0.500 mol/L x 1.50 L = 0.750 mol
1 mol of H₂SO₄ reacts with 2 mol of NaOH
therefore 0.750 mol of H₂SO₄ reacts with - 2 x 0.750 = 1.50 mol of NaOH
molarity of NaOH solution is 0.750 M
there are 0.750 mol in 1 L of solution
therefore 1.50 mol in - 1.50 mol / 0.750 mol/L = 2 L

2 L of NaOH is required for neutralisation 

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.