Unit 12 Nouns

2. A machine that can do the work of a person and that works automatically or is controlled by a computer
4. The process of improving or developing something over a period of time
6. A tall pole that supports or holds something
7. A person who travels in space
9. A chemical that is found in the air, that has no color, taste, or smell, and that is necessary for life
11. beam A beam of nearly parallel and monochromatic light moving in phase
12. A tool or device used for a particular purpose
15. Something that is made to look, feel, or behave like something else especially so that it can be studied or used to train people
16. A small robotic space probe that can move about the surface of a planet or moon.
17. The distance across the center of an object
18. Amount of matter in an object.
21. A device used to capture images.
22. Garbage; rubbish.

1. Outer layer or skin.
3. Something that prevents one from moving forward
5. Process to allow fresh air to enter and move through a room, building, etc.
8. A group of related parts that move or work together
10. A visual image taken by a camera
13. 1,000,000
14. Supplies or tools needed for a special purpose
17. The amount of space between two places or things
19. A dry substance made up of very tiny pieces of something
20. The distance that an airplane or other vehicle can travel before it needs more fuel