| A | B |
|---|
| ATOMS | SMALLEST UNIT OF MATTER WITH PROPERTIES OF SINGLE ELEMENT |
| ELEMENT | PURE SUBSTANCE OF ONE TYPE OF ATOM |
| COMPOUND | 2 OR MORE SUBSTANCES CHEMICALLY COMBINED |
| NUCLEUS | center of an atom; made up of protons and neutrons |
| ATOMIC MASS | weighted average mass of element's isotopes |
| ISOTOPE | variation of an element that has the same number of protons but different number of neutrons |
| DALTON | all matter is made up of atoms and all atoms of specific elements are identical |
| RUTHERFORD | discovered the nucleus and positive protons inside of it |
| Thompson | plum pudding model: discovered electrons with negative charge that are mixed into the positive sphere of an atom |
| BOHR | Planetary model: electrons move around the nucleus in static orbits |
| SCHRODINGER | Electron Cloud Model: neutrons inside nucleus with protons, electrons move in 3 dimensional paths around nucleus |
| MENDELEEV | father of periodic table: determined the relationship of elements to organize them into a table |
| MOSLEY | determined the atomic number NOT atomic weight determined order of elements in the periodic table |
| DEMOCRITUS | STATED ATOMS ARE SMALL, HARD, INDIVISIBLE AND INDESTRUCTIBLE PARTICLES |
| LAVOISIER | KNOW AS THE FATHER OF MODERN CHEMISTRY, GENERATED LIST OF 33 ELEMENTS, & DEVISED THE METRIC SYSTEM |
| DALTON | ATOMIC MODEL OF ATOM WAS BILLIARD BALL |
| ELECTRON | NEGATIVELY CHARGED SUBATOMIC PARTICLE |
| CATHODE RAY TUBE | a high-vacuum tube in which cathode rays produce a luminous image on a fluorescent screen, used in televisions and computer terminals. |
| RUTHERFORD | DISCOVERED PROTONS |
| CHADWICK | DISCOVERED NEUTRONS |
