Homework 7/8/13

1.

1. physical
2. chemical
3. chemical 
4. physical

2.

1. physical
2. physical 
3. physical
4. chemical 

3. 

1. chemical 
2. physical 
3. chemical 
4. physical

4. 

1. chemical
2. chemical 
3. physical  
4. physical

5. A is a chemical change because the color of the apple, which turned brown, is permanent. B is a chemical change because if they loose their charge, thermal energy has been given off. C is a physical change because the oils are removed, but the material remains the same. D is a physical change because the salad dressing separates, but the material remains the same. 

6. 

a. When making chocolate chip cookies you mix flour, milk, eggs, sugar, and chocolate chips together in a bowl. Then you separate the batter into little circles and put it in the oven to bake. Then the cookies must be taken out of the oven to cool.

b. Mixing all the ingredients is just a physical change because although the ingredients are mixed, the materials stay the same. Baking the cookies is a chemical change because it is a permanent temperature change and forms a solid. Taking out the cookies to cool is a physical change because the cookies do not change, although it appears to have changed. 

7. 

a. metals

b. non-metals 

c. non-metals

d. metals

8. 

a. metal

b. metalloid

c. non-metal

d. metal 

9. Boron (B) and silicon (Si). 

10. 

a. idoine is a nonmetal so it would shattter.

b. zirconium is a metal, so it would flatten. 

c. phosphorus is a nonmetal, so it would shatter.

d. nickel is a metal, so it would flatten. 

11. Nonmetals do not conduct electricity and are not malleable; therefore, nonmetal wiring would not be able to bend or transmit electricity. 

12. Metals are suitable for use in coins because they do not break, just bend, they are shiny, and are malleable. 

1.