HESI A2
HESI A2 Version 1 Chemistry Questions
Question 1 of 5
How can water be boiled at room temperature?
Correct Answer: B
Rationale: Water boils when its vapor pressure equals the atmospheric pressure. By increasing the pressure, the atmospheric pressure is reached at a lower temperature, allowing water to boil at room temperature. This phenomenon is utilized in specific scenarios such as high-altitude cooking where the reduced atmospheric pressure requires an increase in the boiling point to cook food properly. Therefore, the correct answer is by increasing the pressure.
Question 2 of 5
What is the name for the horizontal rows of the periodic table?
Correct Answer: B
Rationale: In the periodic table, the horizontal rows are called 'periods.' These periods represent the number of electron shells an element has. Each period starts a new energy level, indicating the elements' properties and atomic structure. 'Groups' refer to the vertical columns of the periodic table, each containing elements with similar chemical properties. 'Families' can also be used interchangeably with groups. 'Sets' is a vague term and not specifically related to the layout of the periodic table. Understanding the distinction between 'periods' and 'groups' is crucial in comprehending the organization and properties of elements in the periodic table.
Question 3 of 5
What can be predicted by using the periodic table?
Correct Answer: A
Rationale: The periodic table is a fundamental tool in chemistry that organizes elements based on their properties. By using the periodic table, scientists can predict the properties of each element. The arrangement of elements in the table groups together elements with similar characteristics, allowing for the prediction of various properties such as reactivity, atomic size, and electronegativity. These predictions are possible because elements in the same group or period exhibit similar chemical behaviors. Therefore, the correct answer is A: The properties of each of the elements.
Question 4 of 5
How can water be boiled at room temperature?
Correct Answer: B
Rationale: Water boils when its vapor pressure equals the atmospheric pressure. By increasing the pressure, the atmospheric pressure is reached at a lower temperature, allowing water to boil at room temperature. This phenomenon is utilized in specific scenarios such as high-altitude cooking where the reduced atmospheric pressure requires an increase in the boiling point to cook food properly. Therefore, the correct answer is by increasing the pressure.
Question 5 of 5
What is the atomic number?
Correct Answer: B
Rationale: The atomic number is the number of protons in an atom's nucleus. It uniquely identifies an element and determines its chemical properties. The number of neutrons and electrons can vary in an atom, but the number of protons remains constant for a specific element. Therefore, the correct answer is the 'Number of protons' (Choice B).