Do objects weigh less on earth then on mercury

What is the maximum amount of al2(so4)3 which could be formed from 15.84 g of al and 12.89 g of cuso4?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)