Re: Why is there more Nitrogen gas present in the air than Oxygen?

Animals, including humans, need oxygen to survive,
but there is such a thing as too much.  Nitrogen is necessary
to keep us from breathing in too much oxygen, which can cause
oxygen toxicity.  Symptoms of oxygen toxicity include:  muscle
twitching and spasm; nausea and vomiting; dizziness; tunnel
vision; tinnitus; irritability, confusion; extreme anxiety;
fatigue; coordination problems; convulsions; and death.

Nitrogen in molecular form is practically inert for humans
(animals metabolize oxygen, while plants metabolize carbon
dioxide) and it came to be the most abundant atmospheric gas
because of volcanic outgassing and biological waste.  Nitrogen
is an essential element of life --- it's part of DNA.  The
noble gases like helium don't occur in nearly enough quantity
to be useful to animals in preventing oxygen toxicity.