what is atomic mass
Logo

Nursing Elites

HESI A2

HESI A2 Chemistry

1. What is atomic mass?

Correct answer: B

Rationale: Atomic mass, also known as atomic weight, is the sum of the number of protons and neutrons in an atom. It represents the average mass of an atom of an element, taking into account the different isotopes and their relative abundance. Neutrons contribute to the atomic mass alongside protons, while the number of neutrons alone is not the definition of atomic mass. Choice A is incorrect because it refers only to the number of protons, not the complete atomic mass. Choice C is incorrect as it focuses solely on the number of neutrons, excluding the contribution of protons. Choice D is incorrect as it mentions the 'average weight of an element,' which is related to atomic mass but does not encapsulate the specific definition of atomic mass as the sum of protons and neutrons.

2. What is the normal body temperature in Fahrenheit?

Correct answer: B

Rationale: The normal body temperature for humans is 98.6°F, which is equivalent to 37°C. This temperature is considered the average baseline for most individuals when measured orally. Choice A (96°F) is too low for normal body temperature. Choice C (100°F) is too high for normal body temperature. Choice D (95°F) is also lower than the normal body temperature range. Therefore, the correct answer is B, 98.6°F.

3. What are neutral particles called?

Correct answer: A

Rationale: Neutral particles, which have no electric charge, are known as neutrons. Neutrons are found in the nucleus of an atom along with protons. Electrons carry a negative charge and orbit the nucleus. Cations are positively charged ions formed by losing electrons. Therefore, the correct answer is 'Neutrons' as they are the neutral particles in an atom, unlike protons, electrons, or cations.

4. 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.

5. Which substance forms hydroxide ions when placed in water?

Correct answer: D

Rationale: The correct answer is D, lye. Lye, also known as sodium hydroxide (NaOH), is a strong base that forms hydroxide ions (OH-) when placed in water. When lye dissolves in water, it dissociates into sodium ions (Na+) and hydroxide ions, making it an alkaline substance. Lemon juice, battery acid, and vinegar do not form hydroxide ions when placed in water. Lemon juice contains citric acid, battery acid contains sulfuric acid, and vinegar contains acetic acid, none of which produce hydroxide ions when dissolved in water.

Similar Questions

How many pairs of electrons are shared between two atoms in a single bond?
Which of these elements has the greatest atomic mass?
The molar mass of glucose is 180 g/mol. If an IV solution contains 5 g of glucose in 100 g of water, what is the molarity of the solution?
What charge do Group VIIA elements have?
What creates a dipole in a covalent bond?

Access More Features

HESI A2 Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

HESI A2 Premium
$149.99/ 90 days

  • Actual HESI A2 Questions
  • 3,000 questions with answers
  • 90 days access

Other Courses