| A | B |
|---|
| atom | the smallest particle that can still be considered an element |
| atomic theory | this has changed over time based on new experimental evidence |
| electrons | negatively charged particles that exist in the atom's cloud |
| nucleus | the center of an atom that contains positive charges |
| protons | positively charged particles in an atom's nucleus |
| energy level | the specific amount of energy responsible for an electron's movement |
| neutron | this particle exists in the nucleus of an atom and has no electric charge |
| atomic number | the number of protons in the nucleus of an atom |
| atomic structure | describes how an atom is built |
| particles | protons, neutrons, and electrons are called |
| electron cloud model | the modern model of an atom |
| a proton's charge | + 1 |
| an electron's charge | - 1 |
| a neutron's charge | no charge - 0 |
| atomic mass units (amu) | the unit of an atom's mass |
| the number of _________ in an atom tells us what element the atom is | protons |
| every __________ has a different atomic number | element |
| these make up almost all the mass of an atom | protons and neutrons |
| atoms with the same number of protons but different numbers of neutrons | isotopes |
