| A | B |
|---|
| Element | a pure substance made of only one kind of atom |
| Periodic Table of Elements | the chart scientists use to organize all the known elements |
| Atomic Number | number of protons |
| Atomic Mass | number of protons & neutrons |
| Element Symbol | One or two letters for the element. |
| Groups | Elements in the same column |
| Periods | A horizontal row of elements in the periodic table |
| Properties | characteristics used to describe a substance |
| Electron Shell | a grouping of electrons surrounding the nucleus of an atom |
| Outer Electron Shell | The electron shell which is furthest away from the nucleus. |
| Atomic Bonding | The linking together of atoms to form larger structures (molecules, compounds) |
| Molecule | Two or more atoms bonded together (can be the same type of atom or different types of atoms) |
| Compound | Two or more DIFFERENT types of atoms bonded together |
| Mixture | Two or more substances mixed together, but NOT bonded |
| Physical Change | A change in matter that does not produce any new products. The appearance of a substance changes, but not the chemical makeup. |
| Chemical Change | A change in matter that produces new products. The chemical makeup of the substance CHANGES. |
| Chemical Equation | set of symbols and formulas that describe a chemical change/chemical reaction |
| Reactant(s) | a substance that takes part in a chemical reaction. |
| Product(s) | a substance that is produced in a chemical reaction. The arrow points to the product(s). |
| Arrow in a chemical equation | Means "produces" or "yields". The arrow shows that a reaction is happening. |
