Which best describes the mass of protons, neutrons and electrons

Calculate the change in entropy if br2(l) is converted into gaseous br atoms. s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

What is the number of atoms in 3.54 mol s

What is the overall order of reaction for rate = k[no]2[o2]