The amount of a harmful chemical to which a person is exposed is the a. dose.
b. response.
c. pollutant.
d. toxin.

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Why is it important to study each branch of earth science?

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers