HESI A2 Chemistry Test
25 Questions
Step-by-step Answer Explanations
Pass Guarantee
LATEST UPDATE
, 1. 1. Question
Express the number 5,400,000 in scientific notation.
54 × 10⁵
5.4 × 10⁶
5.4 × 10⁵
5.4 × 10⁷
Correct Answer
5.4×106
Scientific notation expresses large or small numbers in a compact form.
The notation is structured as:
Significand×10Exponent
where the significand is between 1 and 10, and the exponent reflects how far the decimal
point moves.
Step 1: For 5,400,000, shift the decimal six places left, making it 5.4.
5,400,000. → 5.400,000 → 5.4
Step 2: Since the decimal was moved left, the exponent is positive, giving us:
5.4×106
5.4×105 is incorrect because it equals 540,000, not 5,400,000.
5.4×107 is incorrect because it represents 54,000,000, not 5,400,000.
54×105 is incorrect because the significand (54) is not between 1 and 10, violating scientific
notation rules.
2. 2. Question
In a saltwater solution, what is the solvent?
, Water
Chlorine
Salt
Sodium chloride
Correct Answer
Water
In a solution, two main components are present: the solute and the solvent.
The solvent is the substance that dissolves the solute and is typically present in a larger
amount. It acts as the medium in which the solute particles are dispersed. In an aqueous (water-
based) solution, water is always the solvent. Because water has strong polarity, it can dissolve
many substances, earning it the title “universal solvent.”
The solute is the substance that gets dissolved in the solvent. In a saltwater solution,
the solute is the salt (sodium chloride) that disperses throughout the water.
In the case of a saltwater solution, water dissolves salt by surrounding its ions (sodium and
chloride) and breaking apart its ionic bonds, dispersing the ions evenly throughout the solution.
Therefore, water is the solvent in a saltwater solution.
Salt is incorrect because salt (sodium chloride) is the solute being dissolved.
Sodium chloride is incorrect for the same reason—it’s the solute.
Chlorine is incorrect because chlorine is part of sodium chloride, not the solvent.
3. 3. Question
What particle is emitted during beta decay?
Alpha particle
Neutron
Proton
Electron
Correct Answer
25 Questions
Step-by-step Answer Explanations
Pass Guarantee
LATEST UPDATE
, 1. 1. Question
Express the number 5,400,000 in scientific notation.
54 × 10⁵
5.4 × 10⁶
5.4 × 10⁵
5.4 × 10⁷
Correct Answer
5.4×106
Scientific notation expresses large or small numbers in a compact form.
The notation is structured as:
Significand×10Exponent
where the significand is between 1 and 10, and the exponent reflects how far the decimal
point moves.
Step 1: For 5,400,000, shift the decimal six places left, making it 5.4.
5,400,000. → 5.400,000 → 5.4
Step 2: Since the decimal was moved left, the exponent is positive, giving us:
5.4×106
5.4×105 is incorrect because it equals 540,000, not 5,400,000.
5.4×107 is incorrect because it represents 54,000,000, not 5,400,000.
54×105 is incorrect because the significand (54) is not between 1 and 10, violating scientific
notation rules.
2. 2. Question
In a saltwater solution, what is the solvent?
, Water
Chlorine
Salt
Sodium chloride
Correct Answer
Water
In a solution, two main components are present: the solute and the solvent.
The solvent is the substance that dissolves the solute and is typically present in a larger
amount. It acts as the medium in which the solute particles are dispersed. In an aqueous (water-
based) solution, water is always the solvent. Because water has strong polarity, it can dissolve
many substances, earning it the title “universal solvent.”
The solute is the substance that gets dissolved in the solvent. In a saltwater solution,
the solute is the salt (sodium chloride) that disperses throughout the water.
In the case of a saltwater solution, water dissolves salt by surrounding its ions (sodium and
chloride) and breaking apart its ionic bonds, dispersing the ions evenly throughout the solution.
Therefore, water is the solvent in a saltwater solution.
Salt is incorrect because salt (sodium chloride) is the solute being dissolved.
Sodium chloride is incorrect for the same reason—it’s the solute.
Chlorine is incorrect because chlorine is part of sodium chloride, not the solvent.
3. 3. Question
What particle is emitted during beta decay?
Alpha particle
Neutron
Proton
Electron
Correct Answer
