Science & Technology

1. A material prepared in ancient Egypt from the pithy stem of a water plant, used in sheets throughout the ancient Mediterranean world for writing or painting on and also for making rope, sandals, and boats.
2. The active immature form of an insect, esp. one that differs greatly from the adult and forms the stage between egg and pupa, e.g., a caterpillar or grub.
4. Fine parchment made originally from the skin of a calf.
7. Of, relating to, or denoting the later part of the Stone Age, when ground or polished stone weapons and implements prevailed.
8. Relating to or involving exploration or investigation.
10. Denoting substances (esp. synthetic resins) that set permanently when heated.
11. An integrated circuit that contains all the functions of a central processing unit of a computer.
14. A soft metal core made into a magnet by the passage of electric current through a coil surrounding it.
17. The continuous flow of charged particles from the sun that permeates the solar system.
18. A Japanese battle cry.
19. fission A nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.
20. A band of colors, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.

1. A tough synthetic resin made by polymerizing tetrafluoroethylene, used to coat nonstick cooking utensils and to make seals and bearings.
3. A subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
5. A group of islands in the Pacific off South America; owned by Ecuador; known for unusual animal life
6. A small two-winged fly that is often seen in swarms near water or marshy areas where it breeds.
9. a container with a flat base and sides, typically square or rectangular and having a lid.
12. The layer of the earth's atmosphere that contains a high concentration of ions and free electrons and is able to reflect radio waves. It lies above the mesosphere and extends from about 50 to 600 miles (80 to 1,000 km) above the earth's surface.
13. A seed-eating songbird that typically has a stout bill and colorful plumage.
15. Of or relating to money or currency.
16. Consisting of or characterized by fibers.
21. A device used for calling people around the world