Nursing Elites

1. What is the oxidation state of the oxygen atom in the compound NaOH?

• A. -2
• B. -1
• C. 0
• D. +2

Correct answer: B

Rationale: In the compound NaOH (sodium hydroxide), the oxidation state of the sodium ion (Na) is +1 as it commonly has a +1 charge in ionic compounds. Oxygen (O) typically has an oxidation state of -2 in most compounds. Since the compound is electrically neutral and the overall charge is zero, the sum of the oxidation states of all atoms in the compound must be zero. Therefore, considering that sodium has an oxidation state of +1, the oxygen atom in NaOH must have an oxidation state of -1 to balance the charges and overall neutrality of the compound. Choice A (-2) is incorrect as this is not the oxidation state of oxygen in this compound. Choice C (0) is incorrect as oxygen in NaOH does not have an oxidation state of 0. Choice D (+2) is incorrect as oxygen typically has a negative oxidation state in compounds, not a positive one.

2. What are the three types of radiation?

• A. Alpha, beta, gamma
• B. Alpha, beta, delta
• C. Gamma, delta, epsilon
• D. Beta, gamma, epsilon

Correct answer: A

Rationale: The correct answer is Alpha, beta, gamma. Alpha radiation consists of helium nuclei, beta radiation comprises electrons or positrons, and gamma radiation is high-energy electromagnetic radiation. Choice B, delta, is incorrect as delta is not a type of radiation. Choice C, gamma, delta, epsilon, and Choice D, beta, gamma, epsilon, are incorrect as they do not include the three standard types of radiation.

3. What is the term used when an atom gains one or more electrons?

• A. Cation
• B. Anion
• C. Isotope
• D. Electron

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.

4. What charge do Group IIA elements typically have?

• A. 1
• B. +2
• C. -3
• D. 0

Correct answer: B

Rationale: Group IIA elements belong to the alkaline earth metals group in the periodic table. These elements typically have a charge of +2 because they readily lose two electrons to achieve a stable electron configuration. Therefore, the correct answer is B - +2. Choice A (1) is incorrect because Group IIA elements lose two electrons, not one. Choice C (-3) is incorrect because Group IIA elements do not gain electrons to have a negative charge. Choice D (0) is incorrect because Group IIA elements do lose electrons and have a positive charge, not a neutral charge.

5. What is the correct electron configuration for magnesium?

• A. 1s² 2s²
• B. 1s² 2s² 2p⁶
• C. 1s² 2s² 2p⁶ 3s²
• D. 1s² 2s² 2p⁶ 3s² 3p¹

Correct answer: C

Rationale: The electron configuration of an element is determined by following the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level. Magnesium has an atomic number of 12, meaning it has 12 electrons. The electron configuration of magnesium fills the 1s, 2s, 2p, and 3s orbitals to accommodate all 12 electrons. Therefore, the correct electron configuration for magnesium is 1s² 2s² 2p⁶ 3s². Choice A is incorrect as it only includes 4 electrons and stops at the 2s orbital. Choice B is incorrect as it includes 8 electrons and stops at the 2p orbital. Choice D is incorrect as it includes 13 electrons and extends to the 3p orbital, which is beyond the actual electron configuration of magnesium.

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