HESI A2 CHEMISTRY A2 NURSING SCHOOL ENTANCE ACTUAL EXAM EXAM
NEWEST VERSION 2026-2027 EXPECTED QUESTION AND CORRECT ANSWER
FROM VERIFIED SOURCES RATED A GRADE.
QUESTION
An average of the masses of each of the isotopes of an element as they occur in
nature. (Represents the number of protons and the number of neutrons in an
element because electrons essentially have no mass).
CORRECT ANS: Atomic Weight/Atomic mass number
Expert Rationale
Atomic weight, also known as atomic mass, is the weighted average mass of the
atoms in a naturally occurring sample of an element. It is calculated by taking into
account the relative abundance of each isotope and its individual mass. This value
is expressed in atomic mass units (amu) and is typically a decimal number (e.g.,
carbon is 12.011 amu). The atomic mass number (or mass number) is the total
number of protons and neutrons in a specific isotope's nucleus. Electrons
contribute negligibly to the mass, so the mass number essentially represents the
sum of protons and neutrons.
DIF: Cognitive Level: Understand (Comprehension) TOP: Atomic Structure MSC:
N/A
QUESTION
What group has a +1 charge
CORRECT ANS: IA
,Expert Rationale
Group IA elements, also known as the alkali metals (lithium, sodium, potassium,
rubidium, cesium, and francium), have one valence electron. They lose this single
electron to achieve a stable electron configuration, resulting in a +1 charge. This is
a fundamental property of the periodic table, where elements in the same group
have the same number of valence electrons and similar chemical properties.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
What group has a +2 charge
CORRECT ANS: IIA
Expert Rationale
Group IIA elements, the alkaline earth metals (beryllium, magnesium, calcium,
strontium, barium, and radium), have two valence electrons. They lose these two
electrons to achieve a stable electron configuration, resulting in a +2 charge. This
loss of two electrons gives them a +2 oxidation state in ionic compounds.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
What group has a +3 charge
CORRECT ANS: IIIA
Expert Rationale
Group IIIA elements (boron, aluminum, gallium, indium, and thallium) have three
,valence electrons. They typically lose these three electrons to achieve a stable
configuration, resulting in a +3 charge. Although some heavier elements in this
group can exhibit +1 oxidation states due to the inert pair effect, the most
common and stable charge for this group is +3.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
Density of an object relative to water
CORRECT ANS: Specific Gravity
Expert Rationale
Specific gravity is a dimensionless quantity defined as the ratio of the density of a
substance to the density of a reference substance, usually water at 4°C for liquids
and solids. It indicates whether a substance will sink or float in water. A specific
gravity less than 1 indicates the substance is less dense than water and will float; a
specific gravity greater than 1 indicates it will sink. This property is useful for
identifying substances and is closely related to density.
DIF: Cognitive Level: Remember (Knowledge) TOP: Properties of Matter MSC: N/A
QUESTION
Energy of motion
CORRECT ANS: Kinetic Energy
Expert Rationale
Kinetic energy is the energy an object possesses due to its motion. It depends on
, both the mass of the object and its velocity, as described by the equation KE =
½mv². Any moving object, from a rolling ball to the molecules in a gas, possesses
kinetic energy. It is the opposite of potential energy, which is stored energy.
DIF: Cognitive Level: Remember (Knowledge) TOP: Energy MSC: N/A
QUESTION
Stored energy
CORRECT ANS: Potential Energy
Expert Rationale
Potential energy is the stored energy of an object due to its position, condition, or
composition. This includes gravitational potential energy (energy due to height),
elastic potential energy (energy stored in a stretched spring), and chemical
potential energy (energy stored in chemical bonds). This energy is "potential"
because it has the potential to do work when released.
DIF: Cognitive Level: Remember (Knowledge) TOP: Energy MSC: N/A
QUESTION
Form of energy, measured in calories
CORRECT ANS: Heat
Expert Rationale
Heat is a form of energy that is transferred between systems or objects with
different temperatures. It is the kinetic energy of the random motion of
molecules. The calorie is a unit of measurement for heat energy, defined as the
NEWEST VERSION 2026-2027 EXPECTED QUESTION AND CORRECT ANSWER
FROM VERIFIED SOURCES RATED A GRADE.
QUESTION
An average of the masses of each of the isotopes of an element as they occur in
nature. (Represents the number of protons and the number of neutrons in an
element because electrons essentially have no mass).
CORRECT ANS: Atomic Weight/Atomic mass number
Expert Rationale
Atomic weight, also known as atomic mass, is the weighted average mass of the
atoms in a naturally occurring sample of an element. It is calculated by taking into
account the relative abundance of each isotope and its individual mass. This value
is expressed in atomic mass units (amu) and is typically a decimal number (e.g.,
carbon is 12.011 amu). The atomic mass number (or mass number) is the total
number of protons and neutrons in a specific isotope's nucleus. Electrons
contribute negligibly to the mass, so the mass number essentially represents the
sum of protons and neutrons.
DIF: Cognitive Level: Understand (Comprehension) TOP: Atomic Structure MSC:
N/A
QUESTION
What group has a +1 charge
CORRECT ANS: IA
,Expert Rationale
Group IA elements, also known as the alkali metals (lithium, sodium, potassium,
rubidium, cesium, and francium), have one valence electron. They lose this single
electron to achieve a stable electron configuration, resulting in a +1 charge. This is
a fundamental property of the periodic table, where elements in the same group
have the same number of valence electrons and similar chemical properties.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
What group has a +2 charge
CORRECT ANS: IIA
Expert Rationale
Group IIA elements, the alkaline earth metals (beryllium, magnesium, calcium,
strontium, barium, and radium), have two valence electrons. They lose these two
electrons to achieve a stable electron configuration, resulting in a +2 charge. This
loss of two electrons gives them a +2 oxidation state in ionic compounds.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
What group has a +3 charge
CORRECT ANS: IIIA
Expert Rationale
Group IIIA elements (boron, aluminum, gallium, indium, and thallium) have three
,valence electrons. They typically lose these three electrons to achieve a stable
configuration, resulting in a +3 charge. Although some heavier elements in this
group can exhibit +1 oxidation states due to the inert pair effect, the most
common and stable charge for this group is +3.
DIF: Cognitive Level: Remember (Knowledge) TOP: Periodic Table MSC: N/A
QUESTION
Density of an object relative to water
CORRECT ANS: Specific Gravity
Expert Rationale
Specific gravity is a dimensionless quantity defined as the ratio of the density of a
substance to the density of a reference substance, usually water at 4°C for liquids
and solids. It indicates whether a substance will sink or float in water. A specific
gravity less than 1 indicates the substance is less dense than water and will float; a
specific gravity greater than 1 indicates it will sink. This property is useful for
identifying substances and is closely related to density.
DIF: Cognitive Level: Remember (Knowledge) TOP: Properties of Matter MSC: N/A
QUESTION
Energy of motion
CORRECT ANS: Kinetic Energy
Expert Rationale
Kinetic energy is the energy an object possesses due to its motion. It depends on
, both the mass of the object and its velocity, as described by the equation KE =
½mv². Any moving object, from a rolling ball to the molecules in a gas, possesses
kinetic energy. It is the opposite of potential energy, which is stored energy.
DIF: Cognitive Level: Remember (Knowledge) TOP: Energy MSC: N/A
QUESTION
Stored energy
CORRECT ANS: Potential Energy
Expert Rationale
Potential energy is the stored energy of an object due to its position, condition, or
composition. This includes gravitational potential energy (energy due to height),
elastic potential energy (energy stored in a stretched spring), and chemical
potential energy (energy stored in chemical bonds). This energy is "potential"
because it has the potential to do work when released.
DIF: Cognitive Level: Remember (Knowledge) TOP: Energy MSC: N/A
QUESTION
Form of energy, measured in calories
CORRECT ANS: Heat
Expert Rationale
Heat is a form of energy that is transferred between systems or objects with
different temperatures. It is the kinetic energy of the random motion of
molecules. The calorie is a unit of measurement for heat energy, defined as the
