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

Environmental differences within ecosystems are generally caused by

Which sentence best describes the relationship between chlorophyll and the chloroplast? a.)chlorophyll is a chemical found in a chloroplast. b.) chloroplast is a chemical found in a chlorophyll. c.) both chlorophyll and chloroplasts are found in animals. d.) both chlorophyll and chloroplasts make carbon dioxide.

What is the most common structure of volcanoes?