HESI A2
HESI A2 Chemistry Questions
Question 1 of 5
Which of these elements has the greatest atomic mass?
Correct Answer: D
Rationale: Among the elements listed, Tungsten (W) has the greatest atomic mass. The atomic mass of Tungsten is approximately 183.84 atomic mass units (amu), while the atomic masses of the other elements listed are as follows: Gold (Au) is around 196.97 amu, Barium (Ba) is approximately 137.33 amu, and Iodine (I) is about 126.90 amu. Therefore, Tungsten (W) has the greatest atomic mass out of the given elements. Gold (Au) has a higher atomic mass than Barium (Ba) and Iodine (I), making choices A, B, and C incorrect.
Question 2 of 5
How many protons does Potassium have?
Correct Answer: B
Rationale: Potassium, with the atomic symbol K, has 19 protons, which is equal to its atomic number. The number of protons determines the element's identity, and in the case of Potassium, it is 19. Choice A (18) is incorrect as it does not correspond to Potassium's proton number. Choice C (20) and Choice D (21) are also incorrect as they do not match the actual number of protons in Potassium.
Question 3 of 5
What is the boiling point of water in °C?
Correct Answer: B
Rationale: The correct answer is 100°C. The boiling point of water in Celsius is 100°C, which is standard at sea level. This is the temperature at which water changes from a liquid to a gas phase under standard atmospheric pressure. Choice A (90°C), Choice C (95°C), and Choice D (80°C) are incorrect because they do not represent the standard boiling point of water at sea level.
Question 4 of 5
What is 0 K equal to in °C?
Correct Answer: B
Rationale: 0 Kelvin, also known as absolute zero, is equal to -273°C. This is the point at which all molecular motion stops, making it the lowest possible temperature on the Kelvin scale. Choice A (-300°C) is incorrect as it is not the correct conversion of 0 K to °C. Choice C (-250°C) and Choice D (-200°C) are also incorrect as they do not correspond to the accurate conversion of 0 K to °C.
Question 5 of 5
Which compound is a Hydrogen or proton donor, corrosive to metals, causes blue litmus paper to become red, and becomes less acidic when mixed with a base?
Correct Answer: B
Rationale: The correct answer is 'Acid.' An acid is a compound that donates protons (H+), is corrosive to metals, and turns blue litmus paper red. When an acid is mixed with a base, they react to form salts and water, resulting in a decrease in acidity. Choices A, C, and D are incorrect because bases accept protons rather than donate them, salts are the products of acid-base reactions, and hydroxides are typically bases, not acids.