Consisting of 3 atoms, water is an example of a triatomic one of these units
American Arthur Compton's work proved the existence of these "particles" of light
Albert Einstein announced his special theory of this in 1905 & his general theory in 1915
Under the oceans, this part of the Earth is generally only 3-5 miles thick
Chalk & limestone are naturally occurring forms of this compound, CaCO3
Ammonia, widely used as a refrigerant & cleaner, is composed of hydrogen & this element
Proteins such as pepsin & rennin that act as catalysts in the body are termed these
All algae contain this green pigment that allows them to perform photosynthesis
It's a piece of metal put in an electrical circuit to melt if current flow is too high
The fastest flying animal is the peregrine species of this bird of prey