CHEM 120 EXAM 1 (CHAMBERLAIN) NEWEST 2026
ACTUAL EXAM TEST BANK| CHEM 120
INTRODUCTION TO GENERAL, ORGANIC &
BIOLOGICAL CHEMISTRY EXAM 1 REVIEW WITH 350
REAL EXAM QUESTIONS AND CORRECT VERIFIED
ANSWERS/ GRADED A+ (MOST RECENT!!)
Q1. How many significant figures are in the measurement
0.004050 m?
A) 3
B) 4
C) 5
D) 6
Correct Answer: B
Rationale: Leading zeros are not significant. 0.004050 → digits
4,0,5,0 are significant (the trailing zero after the decimal counts).
4 significant figures.
Q2. What is the result of 12.34 + 5.6 rounded to the correct
number of decimal places?
A) 17.9
1
,B) 18.0
C) 17.94
D) 17.9
Correct Answer: D
Rationale: 12.34 (2 decimal) + 5.6 (1 decimal) = 17.94. Round
to least precise decimal place (tenths) → 17.9.
Q3. Convert 25.0°C to Kelvin.
A) 248 K
B) 273 K
C) 298 K
D) 298.15 K
Correct Answer: C
Rationale: K = °C + 273.15. 25.0 + 273.15 = 298.15 K. With
3 significant figures → 298 K.
Q4. Which subatomic particle has a negative charge and
negligible mass?
A) Proton
B) Neutron
2
,C) Electron
D) Positron
Correct Answer: C
Rationale: Electrons have a charge of –1 and mass ~1/1836
amu. Protons positive, neutrons neutral.
Q5. What is the density of a substance with mass 15.0 g and
volume 5.0 mL?
A) 0.33 g/mL
B) 3.0 g/mL
C) 10.0 g/mL
D) 75 g/mL
Correct Answer: B
Rationale: Density = mass/volume = 15.0 g / 5.0 mL = 3.0
g/mL (2 significant figures from 5.0 mL).
Q6. How many protons, neutrons, and electrons are in
⁴⁰Ca²⁺?
A) 20 p, 20 n, 18 e
B) 20 p, 20 n, 20 e
3
, C) 20p, 20n, 22e p. p. p. p. p.
D) 40p, 20 n,20e p. p. p. p. p.
Correct Answer: A p. p.
Rationale: Atomic number 20 → 20 protons. Mass number 40 →
p. p. p. p. p. p. p. p. p. p.
neutrons = 40 – 20 = 20. Ca²⁺ has lost 2 electrons → 20 – 2 =
p. p. p. p. p. p. p. p. p. p. p. p. p. p. p. p.
18 electrons.
p.
Q7. Which element is a noble gas?
p. p. p. p. p. p.
A) Oxygen (O) p.
B) Neon (Ne) p.
C) Chlorine (Cl) p.
D) Nitrogen (N) p.
Correct Answer: B p. p.
Rationale: Noble gases are Group 18: He, Ne, Ar, Kr, Xe, Rn.
p. p. p. p. p. p. p. p. p. p. p.
p. Neon is a noble gas. Oxygen is Group 16, Chlorine Group 17,
p. p. p. p. p. p. p. p. p. p. p.
p. Nitrogen Group 15. p. p.
Q8. Convert 3.5 km to meters.
p. p. p. p. p.
A) 35 m p.
B) 350 m p.
4
ACTUAL EXAM TEST BANK| CHEM 120
INTRODUCTION TO GENERAL, ORGANIC &
BIOLOGICAL CHEMISTRY EXAM 1 REVIEW WITH 350
REAL EXAM QUESTIONS AND CORRECT VERIFIED
ANSWERS/ GRADED A+ (MOST RECENT!!)
Q1. How many significant figures are in the measurement
0.004050 m?
A) 3
B) 4
C) 5
D) 6
Correct Answer: B
Rationale: Leading zeros are not significant. 0.004050 → digits
4,0,5,0 are significant (the trailing zero after the decimal counts).
4 significant figures.
Q2. What is the result of 12.34 + 5.6 rounded to the correct
number of decimal places?
A) 17.9
1
,B) 18.0
C) 17.94
D) 17.9
Correct Answer: D
Rationale: 12.34 (2 decimal) + 5.6 (1 decimal) = 17.94. Round
to least precise decimal place (tenths) → 17.9.
Q3. Convert 25.0°C to Kelvin.
A) 248 K
B) 273 K
C) 298 K
D) 298.15 K
Correct Answer: C
Rationale: K = °C + 273.15. 25.0 + 273.15 = 298.15 K. With
3 significant figures → 298 K.
Q4. Which subatomic particle has a negative charge and
negligible mass?
A) Proton
B) Neutron
2
,C) Electron
D) Positron
Correct Answer: C
Rationale: Electrons have a charge of –1 and mass ~1/1836
amu. Protons positive, neutrons neutral.
Q5. What is the density of a substance with mass 15.0 g and
volume 5.0 mL?
A) 0.33 g/mL
B) 3.0 g/mL
C) 10.0 g/mL
D) 75 g/mL
Correct Answer: B
Rationale: Density = mass/volume = 15.0 g / 5.0 mL = 3.0
g/mL (2 significant figures from 5.0 mL).
Q6. How many protons, neutrons, and electrons are in
⁴⁰Ca²⁺?
A) 20 p, 20 n, 18 e
B) 20 p, 20 n, 20 e
3
, C) 20p, 20n, 22e p. p. p. p. p.
D) 40p, 20 n,20e p. p. p. p. p.
Correct Answer: A p. p.
Rationale: Atomic number 20 → 20 protons. Mass number 40 →
p. p. p. p. p. p. p. p. p. p.
neutrons = 40 – 20 = 20. Ca²⁺ has lost 2 electrons → 20 – 2 =
p. p. p. p. p. p. p. p. p. p. p. p. p. p. p. p.
18 electrons.
p.
Q7. Which element is a noble gas?
p. p. p. p. p. p.
A) Oxygen (O) p.
B) Neon (Ne) p.
C) Chlorine (Cl) p.
D) Nitrogen (N) p.
Correct Answer: B p. p.
Rationale: Noble gases are Group 18: He, Ne, Ar, Kr, Xe, Rn.
p. p. p. p. p. p. p. p. p. p. p.
p. Neon is a noble gas. Oxygen is Group 16, Chlorine Group 17,
p. p. p. p. p. p. p. p. p. p. p.
p. Nitrogen Group 15. p. p.
Q8. Convert 3.5 km to meters.
p. p. p. p. p.
A) 35 m p.
B) 350 m p.
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