If you don't eat meat, you can still get your iron. Tofu is a good choice. Or go for beans, like kidney, garbanzo, or white. Food from plants has non-heme iron, which means your body doesn't absorb it as well as the heme type found in meat.
Methane is a compound and therefore does not have any atomic number. It is composed of carbon with atomic number 6 and hydrogen with atomic number 1. Methane is a compound and therefore does not have any atomic number. It is composed of carbon with atomic number 6 and hydrogen with atomic number 1.
The carbon in methane molecules comes in different varieties, or isotopes carbon-12 (12C) and carbon-13 (13C). Each 13C atom has an extra neutron in its nucleus, making them slightly heavier than 12C atoms, so the GCMS can distinguish between methane with 12C and methane with 13C.