Chemistry HESI A2 Practice Test - Nurselytic

Correct Answer: B

Rationale: When an atom gains electrons, it becomes negatively charged and is called an anion. An anion is formed when an atom gains one or more electrons, leading to an excess of negative charge.

Choice A, 'Cation,' is incorrect because a cation is formed when an atom loses electrons, resulting in a positively charged ion.
Choice C, 'Isotope,' refers to atoms of the same element with different numbers of neutrons and is not related to gaining electrons.
Choice D, 'Electron,' is the particle that an atom gains to become an anion, not the term for the atom itself after gaining electrons.

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.

Correct Answer: C

Rationale: An alpha particle consists of two protons and two neutrons, resulting in a total charge of +2 due to the presence of two positively charged protons.
Therefore, the correct answer is C, indicating a charge of +2.

Choices A, B, and D are incorrect because an alpha particle is positively charged due to the two protons it contains, resulting in a charge of +2.

Correct Answer: C

Rationale: Isotopes are atoms of the same element with the same number of protons (which determines the element) but different numbers of neutrons. Both carbon-12 and carbon-14 have 6 protons (hence they are both carbon atoms) but different numbers of neutrons: carbon-12 has 6 neutrons, while carbon-14 has 8 neutrons.
Therefore, the correct answer is the number of neutrons.

Choices A, B, and D are incorrect because isotopes may have different numbers of nuclear particles (protons + neutrons), protons, and mass numbers, respectively.

Correct Answer: D

Rationale: Ionic compounds are composed of positively and negatively charged ions that are held together by strong electrostatic forces. These ions arrange themselves in a repeating pattern to form a stable and orderly structure known as a crystalline shape. This is a characteristic property of ionic compounds, making choice D the correct answer.

Choices A, B, and C are incorrect because ionic compounds typically have high melting points, good conductivity in the molten or dissolved state, and do not involve shared electrons but rather the transfer of electrons between atoms.