| A | B |
|---|
| Atom | smallest part of the nucleus |
| What makes up an atom? | electron,neutron, nucleus, protron |
| Democritus | the first person to suggest the idea of an atom |
| John Dalton | proposed an atomic theory of matter |
| What is the atomic number for hydrogen? | 1 |
| What is the atomic number for Helium? | 2 |
| What is the atomic number for Hydrogen(smallest atomic #)? | 1 |
| Electron | negatively charged particle |
| Neutron | neutral particle |
| Nucleus | center,core of an atom |
| Proton | postively charged particle |
| Atomic number | number of protons in the nucleus of an atom |
| Atomic Mass | total mass of the protons and neutrons in an atom |
| Energy Level | place in the atom where an electrons are most likely to be found |
| First energy level | holds 2 electrons |
| Second energy level | holds 8 electrons |
| Third energy level | hold 18 electrons |
| J.J Thomson | 1st scientist to suggest that atoms contain smaller particles |
| Ernest Rutherford | proposed that an atom is mostly empty space with a small nucleus |
| Neils Bohr | proposed that eletrons occupy specific energy levels as they could orbit the nucleus of an atom |
| Group | vertical column of elements in the periodic table |
| Period | horizontal row of elements in the periodic table |
| Metal | element that has the properties of shiny, luster, ductility and malleability |
| Luster | way a material reflects light(shiny) |
| Malleable | able to be hammered into different shapes |
| Ductile | able to be drawn into thin wires |
| Element | substance that cannot be chemically broken down into simpler substances |
| Compound | substance made up of two or more elements that are chemically combined |
| Mixture | two or more substances that have been physicaly combined |
| Substance | any element or compound |
| Periodic table | elements are arranged in order of atomic number |
| Dmitri Mendeleev | The scientist who constructed the 1st periodic table of elements |
| If an atom has 9 protons than how many electrons does it have? | 9 electrons |
| What type of elements are brittle? | Solid non-mentals |
| Out of protons, neutrons and electrons which one is not found in the nucleus? | electrons |
