Question 1

Which of the following is considered an exact number in chemistry?

Accepted Answer

The number of students in a classroom

Question 2

How many significant figures are in the measurement $$0.00340\ \mathrm{kg}$$?

Accepted Answer

$$3$$

Question 3

Which of the following statements about significant figures is correct?

Accepted Answer

Zeros between nonzero digits are significant.

Question 4

A laboratory balance gives a reading of $$15.00\ \mathrm{g}. $$How many significant figures does this measurement have?

Accepted Answer

$$4$$

Question 5

Which of the following measurements contains exactly four significant figures?

Accepted Answer

$$0.04050$$

Question 6

A patient is administered a dose of $$0.0250\ \mathrm{mg} of a $$drug. How many significant figures does this value have?

Accepted Answer

$$3$$

Question 7

Which of the following is NOT an example of an exact number?

Accepted Answer

The measured length of a table as $$2.50\ \mathrm{m}$$

Question 8

How many significant figures are in the value $$1.019\ \mathrm{g}$$?

Accepted Answer

$$4$$

Question 9

Which of the following best describes the role of significant figures in scientific measurements?

Accepted Answer

They indicate the precision of a measurement.

Question 10

A student records the mass of a sample as $$0.0200\ \mathrm{g}. $$Which rule for significant figures applies to the zeros in this measurement?

Accepted Answer

Trailing zeros after a decimal point are significant.

Question 11

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

Accepted Answer

The number of millimeters in a meter

Question 12

A measurement is recorded as $$0.004560\ \mathrm{g}. $$How many significant figures does this value have?

Accepted Answer

$$5$$

Question 13

Which of the following best explains why exact numbers do not affect the number of significant figures in a calculation?

Accepted Answer

Exact numbers are defined values and have no uncertainty.

Question 14

A scientist measures the volume of a liquid as $$12.30\ \mathrm{mL}. $$How many significant figures are in this measurement?

Accepted Answer

$$4$$

Question 15

Which of the following measurements contains only one significant figure?

Accepted Answer

$$0.004$$

Significant Figures and Exact Numbers in Chemistry

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