The temperature of water recorded as $$22.5$$ $$^\\circC$$

Question 1

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

Accepted Answer

The number of students in a classroom

Question 2

How many significant figures are in the measurement $$0.00450 g$$?

Accepted Answer

3

Question 3

Which of the following zeros is NOT considered significant?

Accepted Answer

Zeros at the beginning of a decimal number

Question 4

A student measures the length of a pencil as $$14.00 cm. $$How many significant figures does this measurement have?

Accepted Answer

4

Question 5

Which of the following statements about significant figures is TRUE?

Accepted Answer

Zeros used as placeholders in large numbers without a decimal point are not significant.

Question 6

Which of the following numbers has exactly three significant figures?

Accepted Answer

$$0.0750$$

Question 7

A laboratory scale gives a reading of $$5.008 kg. $$How many significant figures does this measurement have?

Accepted Answer

4

Question 8

Which of the following is a measured number?

Accepted Answer

The temperature of water recorded as $$22.5$$ $$^\circC$$

Question 9

How many significant figures are in the number $$1.250 \times 10^3$?

Accepted Answer

4

Question 10

Which of the following best describes why the number $$500.$$ has three significant figures?

Accepted Answer

The decimal point indicates that all zeros are significant.

Question 11

A student records the mass of a sample as $$0.070 g. $$Which rule about significant figures applies to the zeros in this number?

Accepted Answer

Zeros at the end of a decimal number are significant.

Question 12

Which of the following is an example of a number obtained by definition?

Accepted Answer

The number of grams in a kilogram

Question 13

A student writes $$0.00320 as$$ $$3.20 \times 10$$^{-3}$$. How many significant figures does this number have?

Accepted Answer

3

Question 14

Which of the following measurements contains an estimated digit?

Accepted Answer

$$4.55 cm $$measured with a ruler

Question 15

Why do exact numbers not affect the number of significant figures in a calculation?

Accepted Answer

They are defined or counted and have no uncertainty.

Question 16

A student measures the volume of a liquid as $$250 mL. $$How many significant figures does this measurement have?

Accepted Answer

2

Question 17

Which of the following best explains why $$0.0025$$ has two significant figures?

Accepted Answer

Zeros at the beginning of a decimal number are not significant.

Question 18

A measurement is recorded as $$1.00 \times 10^2$ mL. How many significant figures does this value have?

Accepted Answer

3

Question 19

Which of the following is NOT a characteristic of measured numbers?

Accepted Answer

They are always exact.

Question 20

A student writes the number $$0.0700 in $$scientific notation as $$7.00 \times 10$$^{-2}$$. How many significant figures does this number have?

Accepted Answer

3

Chemistry and Measurements: Measured Numbers and Significant Figures

Guida di studio - Domande di pratica