When will natural selection occur?
o
a. when there are plenty of resources
o
b. when there is no genetic variation
o
c. when there is limited food
o
d. when there is no competition

C. When there is limited food

when there is no competition

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.