| A | B |
|---|
| Element | a substance that cannot be broken down into other substances by chemical or physical means |
| Atom | the smallest particle of an element |
| Nucleus | the tiny central core of an atom containing the protons and neutrons |
| Proton | a positively charged particle found in the nucleus of an atom |
| Neutron | a particle found in the nucleus of an atom with no charge |
| Electron | a negatively charged particle found outside the nucleus |
| Atomic Number | the number of protons found in the nucleus of an atom |
| Atomic Mass Unit | a measurement that scientists use to weigh the particles that make up an atom |
| Valence Electrons | particles of the atom that are the farthest from the nucleus and are the most loosely held |
| Chemical Bond | a force that holds atoms together when electrons are either transferred or shared |
| Electron Dot Diagram | an element symbol surrounded by dots representing valence electrons |
| Physical Property | can be observed without changing the substance into something else |
| Chemical Property | observed when a substance interacts with another substance |
| Atomic Mass | the average mass of one atom of the element |
| The Periodic Table | an arragement of the elements according to the atomic mass and repeating patterns |
| Symbol | one or two letters used to identify an element |
| Group | a column "family" of elements that all have the same number of valence electrons |
| Period | a row of elements that all have the same number of energy levels |
| Metal | these types of elements will usually give up their valence electrons in a chemical reaction |
| Nonmetal | these types of elements will usually gain or share valence electrons in a chemical reaction |
| Metalloid | share properties with both metals and nonmetals |
| Precipitate | a solid that forms from solution during a chemcial reaction |
| Chemical reaction | a change in matter that produces one or more new substances |
| Endothermic reaction | a reaction that takes heat from the solution, making it feel cooler |
| Exothermic reaction | a reaction that releases energy in the form of heat |
| Molecule | a particle made of two or more atoms bonded together |
| Compound | a substance made of two or more elements that have been chemically combined |
