How many atoms of hydrogen are in 1 molecule of methane (ch4)?

What metric units would you use to measure the thickness of a key

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol

How is the use of hydroelectric power related to the sun