Solutions
| 1. |
Answer 2. You learned that elements cannot be decomposed into anything
simpler. Aluminum is an element. Aluminum (Al) is on the Periodic Table
of Elements. |
| 2. |
Answer 3. Remember, this is the definition of a compound. |
| 3. |
Answer 2. A binary compound consists of only two
elements. Answer 2, CH4
, is made up of only two elements, C and H. The other choices are
wrong because they have more than two elements. Each element starts
with a capital letter. |
| 4. |
Answer 1. You learned that a mixture has two or more substances mixed
together. Soil has minerals, rocks, dirt, bacteria, etc., all mixed together.
Soil is heterogeneous because different parts of the soil have different
amounts of materials. Some parts of the soil have more rocks; some parts
of the soil have less rocks. |
| 5. |
Answer 2. Remember the formula: # calories =
grams T. To find T,
subtract the two temperatures. 15.5C - 14.5C =
1C ; # calories =
grams T, # calories = 10 1 = 10. When the temperature of the
water gets lower, 15.5C to 14.5C, it means water gives off (releases)
calories (heat). |
| 6. |
Answer 4. 1 kilocalorie = 1,000
calories. Therefore, 35 kilocalories =
35,000 calories. |
| 7. |
Answer 3. Remember, you learned that heat flows from a higher
temperature to a lower temperature until both are at the same
temperature. Heat flows from solid B (80C) to solid A (50C) until both
are at the same temperature (about 65C). Solid Bs temperature
decreases. |
| 8. |
Answer 3. Heat of Fusion is the amount of heat needed to change a solid
to a liquid at constant temperature. |