Elements are
a. a chemical substance composed of atoms of two or more different types of atoms
b. substances that are made up of only one type of atom
c. subatomic particles with a positive charge
d. only found on earth

20 points asap! question 1 - in your own words, explain the scientific evidence that supports the plate tectonic theory. question 2 - in your own words, explain why the geological structures in florida are different from the geological structures in colorado.

This is a coral reef ecosystem. many biotic and abiotic factors affect the health of this ecosystem. which set correctly pairs a biotic factor and an abiotic factor?

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased