| A | B |
|---|
| matter | Anything that occupies space and has mass. |
| physical properties | Characteristics that you can observe without changing the matter's chemical composition, such as size, shape, texture and hardenss |
| chemical properties | Characteristics of matter that allow it to change into new substances, such as the ability to burn, rust and decompose. |
| element | A substance that cannot be broken down by chemical processes into simpler substances. Example of this would be iron, aluminum, gold, and oxygen. |
| atom | The smallest particle of an element that has the properties of the element. |
| compound | Two or more different elements linked chemically in definite proportions. Examples of compounds would be salt, sugar, baking soda, vitamins and water. |
| protons | Particles with a relatively large mass and a positive (+) charge. |
| neutrons | Particles with about the same mass as protons and no charge. |
| electrons | Particles with a relatively small mass and a negative (-) charge. |
| energy levels | The regions in which electrons move because the electrons in different regions have different amounts of energy. |
| How many electrons can the outermost energy level of any atom hold? | 8 electrons |
| atomic number | The number of protons in an element. |
| mass number | The number of protons plus neutrons. |
| isotopes | Atoms of the same element that have the same number of protons but different numbers of neutrons. |
| radioactive isotope | an isotope in which the nucleus is highly unstable and breaks apart spontaneously , giving off energy. |
| ionic bond | This forms when ions with opposite charges are attracted to each other. |
| covalent bond | This forms when atoms share electrons. |
| chemical reaction | A process in which substances are changed into new substances by the breaking and forming of chemical bonds. |
| endothermic reaction | Reactions in which energy is absorbed. |
| exothermic reaction | Reactions that release energy |
| solution | This is a uniform mixture of two or more substances. |
| solute | The dissolved substances in a solution. |
| solvent | The dissolving substance in a solution . |
| water | This is an essential part of living. |
| acid | A compound that releases hydrogen ions |
| base | A compound that releases hydroxide ions. |
| salts | Compounds that release ions other than hydrogen ions or hydroxide ions. |
| pH scale | A standard measurement of the concentration of hydrogen ions in a solution. |
