| Term | Definition |
|---|---|
| Matter | Anything that takes up space and has mass. |
| Mass | The material that matter is made up of. |
| Volume | How much room/space an object takes up. |
| Density | Density = Mass/Volume The amount of material matter takes up within a specific space. |
| Atom | Smallest particle of an element, everything is made up of them. |
| Electron | Particle of an atom with a negative charge that moves in the nucleus and has an attractive force to bond with other atoms. |
| Proton | Particle of an atom with a positive charge and is located inside the nucleus. |
| Neutron | Particle of an atom with a neutral charge and is located inside the nucleus. |
| Periodic Table | A large table that identifies and classifies all elements by their chemical and physical properties. |
| Element | A pure substance that cannot be broken down and makes up all matter in the universe. |
| Periods/Rows | Rows that tell you how many shells each element has for the electrons to move around. |
| Groups or Families/Columns | Columns that tell the number of valence electrons an element has. |
| Valence Electrons | The electrons that move on the outer shell of an atoms. |
| Atomic Number | How many protons an element has inside the nucleus (usually is the same number of neutrons and electrons) |
| Atomic Mass | The measurement of the mass for an elements atoms. |
| Chemical Property | The ability of substances to combine with one another to form a new substance. |
| Physical Property | The state of matter and appearance of a substance. |
| Ionic Bond | When elements either lose or gain an electron during bonding |
| Covalent Bond | When elements share electrons during bonding. |
| Chemical Change/Reaction | Elements bond together through the attractive force of electrons creating some type of reaction or change |
| Compound/Molecule | Two or more elements combine together in a specific ratio/pattern creating a whole, new and different substance |
| Mixture | Two or more substances combine together keeping their original properties, they do not change into a new substance/compound |
| Nobel Gases | All of the elements in Group #18 – they are the most stable elements because they have eight electrons in their outer shell |
| Halogens | All of the elements in Group #17 – they are very reactive and bond easily with elements in Group #1 because they have seven valence electrons and want to be stable |
| Alkali Metals | All of the elements in Group #1 – they are very reactive because they have only one valence electron |
| Metalloids | Elements between metals and non-metals that can react either way, they have 3-7 valence electrons |
| Endothermic | A chemical reaction that takes in energy to make the temperature decrease. |
| Exothermic | A chemical reaction that releases energy to make the temperature increase. |
