How many grams is 3.89x10^28 atoms of Sulfur?

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

Which material burns faster? metal aluminum

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.