Can someone help a dude out im stuck on this question

What mass of carbon dioxide is produced from the complete combustion of 4.50×10−3 g of methane?

What is the density of the black hole

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.