Model Answers for worksheets of CH4: SEC1: ELEMENTS

Directed Reading B

SECTION: ELEMENTS

1. B                           11. Metals

2. C                           12. Nonmetals

3. B                           13. Metalloids

4. A                           14. C

5. B                           15. A

6. B                           16. B

7. A                           17. D

8. C                           18. A

9. D                           19. C

10. Elements             20. B

Review

1. Metals are good heat conductors, and nonmetals are poor heat conductors.

3. Possible answers: Yes, because metals conduct electric current and nonmetals don’t. Yes, because electric wires are made of copper or aluminum, which are metals. No, because some metalloids conduct electric current, so it may be possible to use metalloids as wires.

4. The elements are nonmetals because all of the elements that are gases are nonmetals and because metals conduct heat.

5. 100% - (92.7% + 6.9%) = 0.4%