Grand Canyon University CHEM 210 Organic Chemistry I Exam 1
(pdf) | 2026/2027 | Organic Chemistry I Q&A | Chemistry
1. Which of the following is an example of a physical change?
A) Rusting of iron
B) Burning of wood
C) Boiling of water
D) Digestion of food
Correct Answer: Boiling of water
Rationale: Boiling water is a physical change because the water changes
state from liquid to gas, but its chemical composition (H₂O) remains the
same. Rusting, burning, and digestion are chemical changes that result in the
formation of new substances. Physical changes do not alter the chemical
identity of the substance.
2. The SI base unit for mass is the:
A) Gram
B) Liter
C) Meter
D) Kilogram
Correct Answer: Kilogram
Rationale: The kilogram is the SI base unit for mass. The gram is a commonly
used unit but is not the SI base unit. The liter is a derived unit for volume,
and the meter is the SI base unit for length. Understanding SI units is
fundamental to scientific measurement.
,3. How many significant figures are in the measurement 0.005080 grams?
A) 3
B) 4
C) 5
D) 6
Correct Answer: 4
Rationale: Leading zeros are never significant. Captive zeros (between non-
zero digits) and trailing zeros after a decimal point are significant. In
0.005080, the significant figures are 5, 0, 8, and 0 (four total). This rule is
essential for reporting measurements with appropriate precision.
4. The number of protons in an atom is called the:
A) Atomic mass
B) Atomic number
C) Mass number
D) Isotope number
Correct Answer: Atomic number
Rationale: The atomic number (Z) is the number of protons in the nucleus of
an atom. It defines the element. The mass number is the total number of
protons and neutrons. The atomic number is a fundamental property that
distinguishes one element from another.
5. Which subatomic particle has a positive charge?
A) Electron
B) Proton
,C) Neutron
D) Photon
Correct Answer: Proton
Rationale: Protons carry a positive charge (+1) and are located in the
nucleus of an atom. Electrons carry a negative charge, neutrons are neutral,
and photons are particles of light with no charge. The proton's charge is
equal in magnitude to the electron's charge but opposite in sign.
6. Isotopes of the same element have the same number of:
A) Neutrons
B) Protons
C) Electrons only
D) Nucleons
Correct Answer: Protons
Rationale: Isotopes are atoms of the same element that have the same
number of protons but a different number of neutrons. They have the same
atomic number but different mass numbers. This concept is critical for
understanding nuclear chemistry and atomic mass calculations.
7. Which element is a noble gas?
A) Oxygen
B) Neon
C) Nitrogen
D) Sodium
, Correct Answer: Neon
Rationale: Neon (Ne) is a noble gas in Group 8A (18) of the periodic table.
Noble gases have a full valence shell, making them inert and chemically
stable. Oxygen is a nonmetal, nitrogen is a nonmetal, and sodium is an alkali
metal.
8. The elements in Group 1A (1) of the periodic table are known as:
A) Alkali metals
B) Alkaline earth metals
C) Halogens
D) Noble gases
Correct Answer: Alkali metals
Rationale: Group 1A elements are the alkali metals. They are highly reactive
metals. Group 2A are alkaline earth metals, Group 7A are halogens, and
Group 8A are noble gases. The alkali metals have one valence electron and
readily lose it to form cations.
9. Which type of bond involves the sharing of electrons between atoms?
A) Ionic bond
B) Covalent bond
C) Metallic bond
D) Hydrogen bond
Correct Answer: Covalent bond
(pdf) | 2026/2027 | Organic Chemistry I Q&A | Chemistry
1. Which of the following is an example of a physical change?
A) Rusting of iron
B) Burning of wood
C) Boiling of water
D) Digestion of food
Correct Answer: Boiling of water
Rationale: Boiling water is a physical change because the water changes
state from liquid to gas, but its chemical composition (H₂O) remains the
same. Rusting, burning, and digestion are chemical changes that result in the
formation of new substances. Physical changes do not alter the chemical
identity of the substance.
2. The SI base unit for mass is the:
A) Gram
B) Liter
C) Meter
D) Kilogram
Correct Answer: Kilogram
Rationale: The kilogram is the SI base unit for mass. The gram is a commonly
used unit but is not the SI base unit. The liter is a derived unit for volume,
and the meter is the SI base unit for length. Understanding SI units is
fundamental to scientific measurement.
,3. How many significant figures are in the measurement 0.005080 grams?
A) 3
B) 4
C) 5
D) 6
Correct Answer: 4
Rationale: Leading zeros are never significant. Captive zeros (between non-
zero digits) and trailing zeros after a decimal point are significant. In
0.005080, the significant figures are 5, 0, 8, and 0 (four total). This rule is
essential for reporting measurements with appropriate precision.
4. The number of protons in an atom is called the:
A) Atomic mass
B) Atomic number
C) Mass number
D) Isotope number
Correct Answer: Atomic number
Rationale: The atomic number (Z) is the number of protons in the nucleus of
an atom. It defines the element. The mass number is the total number of
protons and neutrons. The atomic number is a fundamental property that
distinguishes one element from another.
5. Which subatomic particle has a positive charge?
A) Electron
B) Proton
,C) Neutron
D) Photon
Correct Answer: Proton
Rationale: Protons carry a positive charge (+1) and are located in the
nucleus of an atom. Electrons carry a negative charge, neutrons are neutral,
and photons are particles of light with no charge. The proton's charge is
equal in magnitude to the electron's charge but opposite in sign.
6. Isotopes of the same element have the same number of:
A) Neutrons
B) Protons
C) Electrons only
D) Nucleons
Correct Answer: Protons
Rationale: Isotopes are atoms of the same element that have the same
number of protons but a different number of neutrons. They have the same
atomic number but different mass numbers. This concept is critical for
understanding nuclear chemistry and atomic mass calculations.
7. Which element is a noble gas?
A) Oxygen
B) Neon
C) Nitrogen
D) Sodium
, Correct Answer: Neon
Rationale: Neon (Ne) is a noble gas in Group 8A (18) of the periodic table.
Noble gases have a full valence shell, making them inert and chemically
stable. Oxygen is a nonmetal, nitrogen is a nonmetal, and sodium is an alkali
metal.
8. The elements in Group 1A (1) of the periodic table are known as:
A) Alkali metals
B) Alkaline earth metals
C) Halogens
D) Noble gases
Correct Answer: Alkali metals
Rationale: Group 1A elements are the alkali metals. They are highly reactive
metals. Group 2A are alkaline earth metals, Group 7A are halogens, and
Group 8A are noble gases. The alkali metals have one valence electron and
readily lose it to form cations.
9. Which type of bond involves the sharing of electrons between atoms?
A) Ionic bond
B) Covalent bond
C) Metallic bond
D) Hydrogen bond
Correct Answer: Covalent bond
