| A | B |
|---|
| Atom | The smallest part of an element that has the properties of that element |
| Nucleus | The central part of the atom where the protons and neutrons are located. Most of the mass of the atom is contained here. |
| Protons | Postively charged subatomic particle. Found in the nucleus of the atom. |
| Neutrons | Neutral (has no charge) subatomic particle. Found in the nucleus of the atom |
| Electrons | Negatively charged subatomic particle. Found outside the nucleus of the atom. |
| Atomic number | The number of protons; identifies the atom. |
| Atomic mass | The number of protons plus neutrons in the atom |
| What element has three protons? | Lithium |
| What atom has an atomic number of 9? | Fluorine |
| At atom has an atomic mass of 7 and an atomic number of 3, how many protons, neutrons and electrons does it have? | Protons = 3; Neutrons = 4; Electrons = 3 |
| How do you find the number of neutrons in an atom? | Atomic Mass - Atomic Number = Number of Neutrons |
| An atom has an atomic mass of 27 and an atomic number of 13; how many neutrons does it have? | 14 |
| Atoms of the same element with a different number of neutrons are called what? | Isotopes |
| How many valence electrons does Litihium have? | 1 |
| Valence electrons | The electrons found in the outermost energy level of an atom. |
| How many valence electrons does Oxygen have? | 6 |
| In a Bohr diagram of Neon, how many energy levels are there and how many electrons are in each energy level? | 2 energy levels; 2 electrons in the first and 8 electrons in the second. |
| In a Bohr diagram of Sodium, how many energy levels are there and how many electrons are in each energy level? | 3 energy levels; 2 electrons in the first, 8 electrons in the second; and 1 electron in the third. |
| Family or Group | The vertical columns in the periodic table |
| Period | The horizontal row going across the periodic table. |
| Bohr | Developed a model of the atom that proposed that electrons orbit the nucleus of the atom in discrete energy levels. |
| Chadwick | Discovered the existence of the neutron. |
| Thomson | Developed the "plum pudding model" of the atom. He believed the atom was made up of a positive core with negatively charged particles stuck within it. |
| Rutherford | By shooting alpha particles at gold foil, Rutherford discovered that the atom was made up of a positively charged dense particle in the center and that the negative particles orbited about the positive nucleus. |
