Atomic mass is the total mass of neutrons and protons in a certain isotope. It is usually called: AMU or atomic mass unit.
Because during combustion reaction, heat energy is released and it's this energy that is converted to work
They like cheese because it is easy to eat and it tases really good
the poly atomic molecule is H2
There can be a lot of meanings for isomers. In this case, we are showing the structural isomers of C₇H₁₆. Based on the chemical formula, CₓH₂ₓ₊₂ it is an alkane. They only differ in the positions of methane branches in the parent carbon chain. Basing on the attached picture, the parent carbon chain is pentane for both isomers. But the methyl branches are on the 2nd & 4th, and 2nd & 3rd carbon for 2,4 - dimethylpentane and 2,3 - dimethylpentane, respectively.