What mass of natural gas (ch4) must you burn to emit 272 kj of heat?

CH4 + 2 O2 ---> CO2 + 2 H2O Q = 891,6 kJ / mol CH4

1 mol CH4 = 16 g

16 g 891,6 kJ
x g 272 kJ

x = 272 kJ × 16 g / 891,6 kJ = 4,88 g

You must burn 4,88 g of CH4.

:-) ;-)

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

The atomic nucleus made up from protons (yellow) and neutrons (blue) and held together by nuclear forces. nuclear forces (also known as nuclear interactions or strong forces) are the forces that act between two or more nucleons. they bind protons and neutrons (“nucleons”) into atomic