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