Temperature and Centigrams Ans

1. It is estimated that uranium is relatively common in the earth’s crust, occurring in amounts of 4 g/metric ton. A metric ton is 1000 kg. At this concentration, what mass of uranium is present in 1.0 mg of the earth’s crust? a) 4 nanograms b) 4 micrograms c) 4 milligrams d) 4 × 10–5 g e) 4 centigrams

Ans: a) 4 nanograms Page: 1.3,6

2. In 1928, 1.0 g of a new element was isolated from 660 kg of the ore molybdenite. The percent by mass of this element in the ore was:

a) 1.5% b) 6.6% c) 1.0% d) 1.5 × 10–4% e) 3.5 × 10–3%

Ans: d) 1.5 × 10–4% Page: 1.3,6

3. Which of the following metric relationships is incorrect?

a) 1 microliter = 10–6 liters b) 1 gram = 103 kilograms c) 103 milliliters = 1 liter d) 1 gram = 102 centigrams e) 10 decimeters = 1 meter

Ans: b) 1 gram = 103 kilograms Page: 1.3

4. Which of the following is an example of a quantitative observation?

a) The piece of metal is longer than the piece of wood b) Solution 1 is much darker than solution 2. c) The liquid in beaker A is blue. d) The temperature of the liquid is 60°C. e) At least two of these (a-d) are quantitative observations.

ANS: d) The temperature of the liquid is 60°C. Page: 1.2 5. A quantitative observation

a) contains a number and a unit. b) does not contain a number. c) always makes a comparison. d) must be obtained through experimentation. e) none of these

ANS: a) contains a number and a unit. Page: 1.3

6. Generally observed behavior which can be formulated into a statement, sometimes mathematical in nature, is called a(n)

a)