$\frac{2.54\ \text{cm}}{1\ \text{in}}$

$44.7 \times \frac{1\ \text{in}}{2.54\ \text{cm}}$

Question 1

Which of the following numbers is correctly written in scientific notation?

Accepted Answer

$2.5 	imes 10^1$

Question 2

A student measures the mass of a sample as 1.260 g using a scale marked every 0.1 g. Which digit is considered estimated?

Accepted Answer

The digit '0'

Question 3

How many significant figures are in the measurement 0.00450 g?

Accepted Answer

3

Question 4

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

Accepted Answer

1 in = 2.54 cm

Question 5

Convert 0.00056 to scientific notation.

Accepted Answer

$5.6 	imes 10^{-4}$

Question 6

Which rule should be followed when rounding the result of a multiplication or division calculation involving significant figures?

Accepted Answer

Round to the same number of significant figures as the input with the fewest significant figures.

Question 7

A chemist adds 5.74 g and 9.213 g. What is the correct answer, reported with the proper number of decimal places?

Accepted Answer

$14.95$

Question 8

Which of the following statements about trailing zeros is correct?

Accepted Answer

Trailing zeros after a decimal point are significant.

Question 9

A measurement is recorded as 100.00 m. How many significant figures does this value have?

Accepted Answer

5

Question 10

Which conversion factor would you use to convert inches to centimeters?

Accepted Answer

$\frac{2.54\ 	ext{cm}}{1\ 	ext{in}}$

Question 11

A student multiplies $2.0$ (2 sig. figs) by $3.56$ (3 sig. figs). What should the answer be, with the correct number of significant figures?

Accepted Answer

$7.1$

Question 12

Which of the following is NOT a step in converting a number to scientific notation?

Accepted Answer

Add zeros to the end of the number to increase its value.

Question 13

A student subtracts $4.8$ from $3.965$. What is the correct answer, reported with the proper number of decimal places?

Accepted Answer

$0.8$

Question 14

Which of the following is an example of dimensional analysis in unit conversion?

Accepted Answer

Multiplying a number by a conversion factor so that units cancel appropriately.

Question 15

How many significant figures are in the number 1.080?

Accepted Answer

4

Question 16

Which of the following is true about leading zeros?

Accepted Answer

Leading zeros are never significant; they only serve to locate the decimal point.

Question 17

A student wants to convert 44.7 cm to inches using the conversion factor $1\ 	ext{in} = 2.54\ 	ext{cm}$. What is the correct calculation?

Accepted Answer

$44.7 	imes \frac{1\ 	ext{in}}{2.54\ 	ext{cm}}$

Question 18

Which of the following statements about rounding in multi-step calculations is correct?

Accepted Answer

Round only the final answer to prevent small rounding errors from affecting the result.

Question 19

A student reports a measurement as 237.1 m. Which digits are considered certain?

Accepted Answer

2, 3, and 7

Question 20

Which of the following is the correct scientific notation for Avogadro's number, $6,022,000,000,000,000,000,000$?

Accepted Answer

$6.022 	imes 10^{23}$

Numbers in Chemistry: Scientific Notation, Significant Figures, and Unit Conversions

Study Guide - Practice Questions