Please help me quickly

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Kc = 0.040 for the system below at 450oc. if a reaction is initiated with 0.40 mole of cl2 and 0.40 mole of pcl3 in a 2.0 liter container, what is the equilibrium concentration of cl2 in the same system? pcl5(g) ⇄ pcl3(g) + cl2(g)

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure