Across
- 4. the smallest part of a compound that is made of individual atoms.
- 5. the shell in which an electron moves around the nucleus of an atom.
- 9. the force that causes one object to pull another object to itself.
- 11. an object that moves in two directions.
- 12. anything that occupies space.
- 13. moving in only one direction.
- 14. electrons located in the outer orbit of an atom.
- 17. the smallest part of an element that contains all the properties of that element.
- 19. the center or middle.
- 20. one of the three principal parts of an atom. Has a positive charge.
- 21. one polarity of a voltage, current, or charge that has an excess of electrons.
Down
- 1. an electric charge developed when an object contains more protons than electrons.
- 2. current that reverses its direction of flow periodically. Reversals generally occur at regular intervals.
- 3. a device or material that permits current to flow through it easily.
- 6. This number is equal to the number of protons (positively charged particles) in the nucleus of an atom.
- 7. current that does not reverse its direction of flow.
- 8. a material used to electrically isolate two conductive surfaces.
- 10. a material that contains four valence electrons and is used in the production of solid-state devices.
- 15. one of the three major parts of an atom. Carries a negative charge.
- 16. the force that causes one object to push another object away from itself.
- 18. (1) one of the basic building blocks of nature. An atom is the smallest part of this; (2) one part of a group of devices.
- 19. one of the principal parts of an atom. Has no charge and is part of the nucleus.