,CHEM 103 Module 1 | Practice Q&A | 2026/2027 | Chemistry |
Portage Learning | 100% PASS
1. Which of the following is defined as anything that has mass and takes up
space?
A) Energy
B) Matter
C) Vacuum
D) Force
Correct Answer: Matter
Rationale: Matter is the physical substance of the universe that possesses
mass and occupies a physical volume, distinguishing it from forms of energy
such as light or heat. A vacuum contains no matter, and force is not a
substance.
2. Convert 845.3 to exponential (scientific notation) form.
A) 84.53 × 10¹
B) 8.453 × 10²
C) 0.8453 × 10³
D) 8453 × 10⁻¹
Correct Answer: 8.453 × 10²
Rationale: To convert to scientific notation, move the decimal point so there
is one non-zero digit to the left of the decimal. 845.3 → 8.453. The decimal
was moved 2 places to the left, so the exponent is +2.
3. Convert 0.0000726 to scientific notation.
,A) 7.26 × 10⁻⁵
B) 7.26 × 10⁵
C) 72.6 × 10⁻⁶
D) 0.726 × 10⁻⁴
Correct Answer: 7.26 × 10⁻⁵
Rationale: Move the decimal point 5 places to the right to get 7.26. Because
the original number is less than 1, the exponent must be negative, resulting
in 7.26 × 10⁻⁵.
4. Convert 3.21 × 10⁻⁵ to ordinary form.
A) 0.0000321
B) 0.000321
C) 321000
D) 0.00000321
Correct Answer: 0.0000321
Rationale: A negative exponent means the number is smaller than 1. Move
the decimal 5 places to the left: 3.21 × 10⁻⁵ = 0.0000321.
5. How many significant figures are in the number 0.01354?
A) 3
B) 4
C) 5
D) 6
, Correct Answer: 5
Rationale: All non-zero digits are significant. Zeros to the left of a decimal or
preceding other non-zero numbers are not significant. 0.01354 has 5
significant figures (1, 3, 5, 4 are all significant; leading zeros are not).
6. How many significant figures are in the number 1300?
A) 1
B) 2
C) 3
D) 4
Correct Answer: 2
Rationale: Without a decimal point, trailing zeros are not significant. 1300
has 2 significant figures (1 and 3). If written as 1300., it would have 4
significant figures.
7. How many significant figures are in the number 520.3?
A) 2
B) 3
C) 4
D) 5
Correct Answer: 4
Portage Learning | 100% PASS
1. Which of the following is defined as anything that has mass and takes up
space?
A) Energy
B) Matter
C) Vacuum
D) Force
Correct Answer: Matter
Rationale: Matter is the physical substance of the universe that possesses
mass and occupies a physical volume, distinguishing it from forms of energy
such as light or heat. A vacuum contains no matter, and force is not a
substance.
2. Convert 845.3 to exponential (scientific notation) form.
A) 84.53 × 10¹
B) 8.453 × 10²
C) 0.8453 × 10³
D) 8453 × 10⁻¹
Correct Answer: 8.453 × 10²
Rationale: To convert to scientific notation, move the decimal point so there
is one non-zero digit to the left of the decimal. 845.3 → 8.453. The decimal
was moved 2 places to the left, so the exponent is +2.
3. Convert 0.0000726 to scientific notation.
,A) 7.26 × 10⁻⁵
B) 7.26 × 10⁵
C) 72.6 × 10⁻⁶
D) 0.726 × 10⁻⁴
Correct Answer: 7.26 × 10⁻⁵
Rationale: Move the decimal point 5 places to the right to get 7.26. Because
the original number is less than 1, the exponent must be negative, resulting
in 7.26 × 10⁻⁵.
4. Convert 3.21 × 10⁻⁵ to ordinary form.
A) 0.0000321
B) 0.000321
C) 321000
D) 0.00000321
Correct Answer: 0.0000321
Rationale: A negative exponent means the number is smaller than 1. Move
the decimal 5 places to the left: 3.21 × 10⁻⁵ = 0.0000321.
5. How many significant figures are in the number 0.01354?
A) 3
B) 4
C) 5
D) 6
, Correct Answer: 5
Rationale: All non-zero digits are significant. Zeros to the left of a decimal or
preceding other non-zero numbers are not significant. 0.01354 has 5
significant figures (1, 3, 5, 4 are all significant; leading zeros are not).
6. How many significant figures are in the number 1300?
A) 1
B) 2
C) 3
D) 4
Correct Answer: 2
Rationale: Without a decimal point, trailing zeros are not significant. 1300
has 2 significant figures (1 and 3). If written as 1300., it would have 4
significant figures.
7. How many significant figures are in the number 520.3?
A) 2
B) 3
C) 4
D) 5
Correct Answer: 4
