| A | B |
|---|
| chemical symbol | letter(s) representing the name of an element |
| nucleus | contains protons and neutrons |
| atomic number | number of protons in nucleus |
| mass number | number of protons and neutrons in nucleus |
| electrons | negatively charged particles that travel around outside of nucleus |
| isotope | atom with different number of neutrons |
| energy levels | only contain a maximum number of electrons |
| groups or families | vertical columns of periodic table, share common properties |
| periods | horizontal rows of periodic table |
| chemical property | describes how one substance changes when it reacts with another |
| physical property | properties that you can observe without changing the substance |
| density | mass per volume |
| solution | a mixture dissolved in another substance |
| mixture | substances that are mixed together, but retain their own properties |
| ion | charged particle |
| matter | anything that takes up space and has mass |
| atom | building blocks of matter |
| elements | matter that contains only one kind of atom |
| proton | positively charged particle found in the nucleus |
| neutron | neutral particle found in the nucleus |
| molecule | smallest particle of a compound; keeps properties of the compound, made of two or more atoms |
| compound | atoms chemically combine to form new substances with different properties |
