Question 1

Which of the following correctly expresses the number 0.000000000045 in scientific notation?

Accepted Answer

$$4.5 	imes 10$$^{-11}$$

Question 2

A scientist measures the mass of a sample as 0.0450 g. How many significant figures does this measurement have?

Accepted Answer

3

Question 3

Which of the following numbers has an ambiguous number of significant figures?

Accepted Answer

2100

Question 4

The population of a country is 1,387,000,000 people. Express this number in scientific notation.

Accepted Answer

$$1.387 	imes 10$$^{9}$$

Question 5

A graduated cylinder has marks every 0.1 mL. Which measurement reports the correct number of significant figures?

Accepted Answer

2.94 mL

Question 6

Which of the following statements about significant figures is TRUE?

Accepted Answer

Trailing zeros after a decimal point are significant.

Question 7

A measurement is recorded as 0.01010 g. How many significant figures does this value have?

Accepted Answer

5

Question 8

A scientist measures the diameter of a dust speck as $$4.5 	imes 10$$^{-5}$$ mm. What is the value of this number in decimal notation?

Accepted Answer

0.000045 mm

Question 9

When adding $$5.24 + 2.1$$, what is the correct answer with the proper number of decimal places?

Accepted Answer

$$7.3$$

Question 10

Which of the following best describes why scientists use scientific notation?

Accepted Answer

To write very large or very small numbers more compactly and clearly.

Question 11

A balance has markings every 0.1 g. If you estimate the mass of an object as 1.26 g, which digit is the estimated digit?

Accepted Answer

6

Question 12

Which of the following is an example of an exact number?

Accepted Answer

The number of centimeters in a meter

Question 13

The Curiosity Rover on Mars measured a daily low temperature of $$-65.19\ ^\circ \mathrm{C}. $$What is the implied range of the actual temperature?

Accepted Answer

between $$-65.19\ ^\circ \mathrm{C}$$ and $$-65.20\ ^\circ \mathrm{C}$$

Question 14

When rounding the number 2.349 to two significant figures, what is the result?

Accepted Answer

2.4

Question 15

Which of the following correctly expresses the sum $$8.796 + 0.01$$ rounded to three significant figures?

Accepted Answer

$$8.81$$

Question 16

How many significant figures are in the measurement 0.00230?

Accepted Answer

3

Question 17

Which of the following is the correct way to write 5,300 in scientific notation with two significant figures?

Accepted Answer

$$5.3 	imes 10$$^{3}$$

Question 18

A thermometer reads 22.7 $$^\circC. If $$the thermometer has markings every 1 $$^\circC$$, what is the correct way to report the temperature?

Accepted Answer

23 $$^\circC$$

Question 19

Which of the following statements about reporting measured quantities is correct?

Accepted Answer

The last reported digit is always uncertain.

Question 20

When multiplying $$3.50 	imes 1.2$$, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$4.2$$

Scientific Notation, Measurement, and Significant Figures in Chemistry

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