| A | B |
|---|
| What an atom is made up of. | Protons, neutrons and electrons |
| Most of the mass of an atom is contained here. | The nucleus. |
| A dense, central core. | Nucleus. |
| The nucleus contains... | Protons and Neutrons |
| A particle with a positive electric charge. | Proton |
| A particle with NO electric charge. | Neutron |
| A particle with a negative Charge | Electron |
| Electrons travel around the nucleus in paths called | Orbits |
| Electrons are thought of as ? surrounding the nucleus because they travel so fast | Clouds |
| The smallest and lightest of the three types of atomic particles | Electrons |
| What gives an atom its chemical properties? | Electrons. |
| What gives an atom its identity? | The number or protons in the nucleus of the atom |
| How many protons does an atom of oxygen have? | Eight (8) |
| The number of protons in an an atom of that element | Atomic Number |
| The balance of negative and positive charges leaves the atom ? | Electrically neutral |
| The attraction between positive and negative charges | Chemical bond |
| An electrically charged atom | Ion |
| When hydrogen reacts with oxygen to form water, two hydrogen atoms and one oxygen atom join up by sharing electrons is an example of this. | Covalent compound |
| What is always involved in the making or breaking of chemical bonds? | Energy |
| Matter can not be created or destroyed by any chemical reaction. | Conservation of Mass. |
| Joseph Priestly & Karl W. Scheele | Discovered oxygen in A.D. 1774 |
| Published the Theory of Relativity | Albert Einstein |
| Establishes the relationship between mass and energy | The Theory of Relativity |
| French Chemist who discovered that when matter burns, it combines with oxygen | Antoine Lavoisier |
| Leucippus and Democritus | Greek Philosophers who first stated the ideas of the Conservation of Mass |
| This person's work with radium, from 1890-1910, increased our understanding of radioactivity | Marie Curie |
| This person discovered radioactivity | Becquerel |
| Made up of atoms whose nuclei break down, or decay, into nuclei of other atoms | A radioactive element |
| Invisible high-energy rays | Gamma Rays |
| The splitting of the nucleus of an atom, releasing great amount of energy. | Nuclear fission |
| This is produced when released neutrons collide with and split other nuclei | Chain reaction |
| A device in which a nuclear chain reaction is controlled | Nuclear reactor |
