| A | B |
|---|
| All elements are composed of atoms | Dalton |
| Atoms of the same element are alike | Dalton |
| Atoms combine to form compounds in whole number ratios | Dalton |
| The nucleus of an atom is _____ | positively charged and has a high density |
| Which subatomic particle has the smalles mass? | electron |
| Which part of Dalton's theory was disproved by the work of Thompson? | atoms are indivisible |
| Most of the mass of the atom is in the center | Rutherford |
| the center of the atom has a positive charge | Rutherford |
| Atoms contain both positively and negatively charged particles | Rutherford |
| _____ is the nuclear particle that is least penetrating. | alpha particles |
| In the fireworks lab, the elements gave off color as their electrons _____ | fell bac to original energy level |
| An electron for which n=4 has more _____ than an electron for which n=2. | energy |
| It is impossible to know both the speed (velocity) and position of the electron simultaneously. | Heisenberg Uncertainty Principle |
| How many unpaired electrons are found in an atom of chlorine in the ground state? | 1 |
| An atom of fluorine contains 9 electrons. How many of these electrons are in s orbitals? | 4 |
| The half-life of radium-226 is 1600 years. How long will it take for 10.0 mg of radium-226 to decay to 1.25 mg? | 1600x3=4800 years (3 half-lives) |
