| A | B |
|---|
| chemistry | the study of matter and the changes it undergoes |
| matter | anything that takes up space and has mass |
| mass | the amount of matter in an object |
| weight | an object's mass and the pull of gravity |
| elements | substances that can't be broken down chemically into simpler kinds of matter |
| atom | the smallest particle of an element that still retains its properties |
| nucleus | center of the atom that contains the protons and neutrons |
| energy levels | space around the nucleus where the electrons are located |
| proton | subatomic particle with a positive charge, found in the nucleus |
| neutron | subatomic particle with no electrical charge, found in the nucleus |
| electron | subatomic particle with a negative electrical charge |
| atomic number | the number of protons in the nucleus of an atom |
