Nursing Elites

1. Which element is considered a noble gas?

• A. Oxygen
• B. Neon
• C. Hydrogen
• D. Argon

Correct answer: B

Rationale: The correct answer is 'Neon.' Noble gases are a group of elements with very low reactivity. Neon is one of these elements, known for its stable and unreactive nature. Oxygen, hydrogen, and argon do not belong to the noble gas group. Oxygen is a reactive non-metal, hydrogen is a non-metal and the first element in the periodic table, and argon is a noble gas like neon but not the correct answer in this case.

2. What is a mole?

• A. 6.02 x 10^23
• B. 1.00 x 10^24
• C. 6.02 x 10^22
• D. 6.02 x 10^25

Correct answer: A

Rationale: A mole is a unit used in chemistry to represent Avogadro's number, which is approximately 6.02 x 10^23. This number corresponds to the number of particles (atoms, molecules, ions) in one mole of a substance. Choice A, 6.02 x 10^23, is the correct answer as it accurately defines a mole. Choices B, C, and D provide values that are not equivalent to Avogadro's number, making them incorrect answers.

3. How many pairs of electrons are shared between two atoms in a single bond?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: A

Rationale: In a single bond, two atoms share one pair of electrons. This shared pair of electrons is what holds the atoms together in the bond. Therefore, the correct answer is A: 1. Choices B, C, and D are incorrect because they do not represent the number of electron pairs shared in a single bond.

4. 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.

5. What are mixtures of 2 or more metals called?

• A. Solutions
• B. Alloys
• C. Compounds
• D. Suspensions

Correct answer: B

Rationale: Alloys are mixtures of two or more metals, combining their properties to create materials with enhanced characteristics. Examples of alloys include bronze (copper and tin) and steel (iron and carbon). Alloys are commonly used in various industries due to their improved strength, durability, and other desirable qualities. Solutions (Choice A) refer to a homogeneous mixture of two or more substances, where one substance is dissolved in another. Compounds (Choice C) are substances composed of two or more elements chemically combined in fixed proportions. Suspensions (Choice D) are heterogeneous mixtures where particles are dispersed but can settle out over time.

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