How many moles would there be in 500 billion atoms of silver

Which substance absorbs 58.16 kj of energy when 3.11 mol vaporizes? a)ch4 b)h2s c)co2 d)nacl

Type the letter that represents the correct location for each particle type below.

20 pts ‼️ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraft’s weight the greatest?