Most important elements on earth: carbon and silicon Allotrope: molecular form of an element that exists in two or more different forms in the same physical state. Examples for carbon: diamonds, graphite, and buckminsterfullerene.
This group has all three different categories of metals: metals, non-metals, metalloids
One method used to isolate pure N2: combine and then distill it from a liquefied oxygen. Liquid nitrogen distills off first because it has a lower boiling point than liquid oxygen.
The Haber process is used to make ammonia by combining hydrogen and nitrogen.
Reaction for the Haber process: N2 (g) + 3H2 (g) ⇔ 2NH3 (g)
N2 is extremely stable because it has a triple bond.D. Group 15 (5a)