Experiments have determined that the average mass of helium is 4.0026 amu. What is the mass defect for the helium atom?

Calculate the change in entropy if br2(l) is converted to br2(g). 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)

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?

Which formula can be used to calculate the molar mass of hydrogen peroxide