All __ are molecules, but only molecules made up of atoms from two or more elements are compounds.
a)ionic compounds
b)atoms
c)elements
d)molecular compounds

How can you tell the difference between rough er from smooth er?

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.

As a result of climate change earths temperature is rising and sea ice is melting what is a likely effect? answer : populations of walruses and polar bears will decline