Atomic History

1. Electrons or the "cloud" accounts for most of the _____ of the atom
7. Bohr suggested that electrons were in ______ orbits or energy levels around the nucleus
8. Greek word meaning "uncuttable"
9. The negatively charged particles
12. Protons, neutrons and electrons are all
16. Chadwick's discovery of neutrons explained why atoms were ________ than the total mas of their protons and electrons
17. Who discovered the first subatomic particle
18. Cloud Model The Modern Model is also called
19. Thomson's model was also known as the
22. Shooting positive charged particles at gold foil is like shooting bullets at

2. A region of an atom in which electrons of the same energy are likely to be found
3. According to Dalton, atoms are invisible and _____________
4. Who offered the first modern theory of the atom
5. Dalton was the first to come up with _____ for elements
6. The Modern Model is based on the types of physics called
10. Who discovered neutrons
11. What famous experiment did Ernest Rutherford perform
13. The original name of electrons that Thomson first called them by
14. The positively charged particles
15. During the time of Democritus which eminent person dismissed the idea of atoms
20. Bohr Who's model resembles the planets orbiting around the sun
21. The central core of the atom
23. Rutherford concluded that the atom was mostly _____ space with electrons moving around the nucleus