CHEMISTRY ASSIGNMENT
THE COMPARATIVE ABUNDANCE OF THE ELEMENTS
· There are 92 naturally occurring elements, only 17 of them make up 99.5% of the earth's crust (including oceans and atmosphere).
· In living things (plants, animals, people) the six most abundant elements are carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur.
· The universe is dominated by the elements hydrogen (83%) and helium (16%)
1. The Crust
The outside of the earth is a thin crust which is approximately 20 to 40km thick. The crust is a formation of dips and hollows which are filled wit…
