how many neutrons does carbon 14 have
Logo

Nursing Elites

HESI A2

Chemistry HESI A2 Practice Test

1. How many neutrons does carbon-14 have?

Correct answer: B

Rationale: The correct answer is B: 8. Carbon-14 is an isotope of carbon with 6 protons and 8 neutrons. To determine the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number. In this case, the mass number of carbon-14 is 14, and the atomic number of carbon is 6. Therefore, 14 (mass number) - 6 (atomic number) = 8 neutrons. Choices A, C, and D are incorrect because they do not reflect the correct number of neutrons in a carbon-14 atom.

2. What charge do Group VIIA elements have?

Correct answer: A

Rationale: Group VIIA elements, also known as halogens, have a tendency to gain one electron to achieve a stable electron configuration, resulting in a -1 charge. This is because they have seven valence electrons and need one more to complete their octet, making them highly reactive in forming -1 ions. Therefore, the correct answer is A. Choice B (-2) is incorrect because Group VIIA elements typically gain one electron, not two. Choice C (0) is incorrect as these elements tend to form -1 ions by gaining one electron. Choice D (1) is incorrect because Group VIIA elements gain electrons to form negative ions, not positive ones.

3. 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.

4. Which element is a metalloid?

Correct answer: A

Rationale: The correct answer is 'Silicon.' Silicon is a metalloid, which means it has properties of both metals and nonmetals. It is commonly used in electronic devices due to its semiconductor properties. Lead (Choice B) is a metal, Helium (Choice C) is a noble gas, and Aluminum (Choice D) is a metal.

5. Which of the following elements is a noble gas?

Correct answer: C

Rationale: The correct answer is C: Argon. Argon is a noble gas, part of Group 18 in the periodic table. Noble gases are colorless, odorless, and typically non-reactive under normal conditions. Other elements in this group include helium, neon, krypton, xenon, and radon. Argon finds wide applications in welding, lighting, and scientific research. Choices A, B, and D are not noble gases. Hydrogen is a non-metal, Fluorine is a halogen, and Nitrogen is a diatomic non-metal gas.

Similar Questions

What is the name of the device that separates gaseous ions by their mass-to-charge ratio?
What are bases or alkaline solutions known as?
What is the main component of air?
Which of these represents a strong acid?
Which of these intermolecular forces would result in the lowest boiling point?

Access More Features

HESI A2 Basic
$89/ 30 days

  • 3,000 Questions with answers
  • 30 days access

HESI A2 Premium
$129.99/ 90 days

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

Other Courses