How do autotrophs obtain CO2 and N2 to make their own food?

Explanation:

CO2 is obtained directly from atmosphere through stomata. N2 can't be taken directly from atmosphere hence it is converted into nitrites and nitrates by process called nitrogen fixation

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.