Nursing Elites

1. What are the products of combustion of a hydrocarbon in excess oxygen?

• A. Carbon dioxide and water
• B. Naphthalene
• C. Chlorine and bromine
• D. Carbonium ions

Correct answer: A

Rationale: The correct answer is A: Carbon dioxide and water. During the combustion of a hydrocarbon in excess oxygen, the hydrocarbon reacts to produce carbon dioxide and water vapor as the final products. This reaction is known as complete combustion, where the hydrocarbon combines with oxygen to form carbon dioxide and water. Choices B, C, and D are incorrect because naphthalene is a specific hydrocarbon compound, chlorine and bromine are not typically formed during the combustion of hydrocarbons in excess oxygen, and carbonium ions are not the products of this reaction.

2. What is the name for the horizontal rows of the periodic table?

• A. groups
• B. periods
• C. families
• D. sets

Correct answer: B

Rationale: In the periodic table, 'periods' are the horizontal rows. Each period corresponds to the energy level occupied by the elements in that row. The other terms mentioned, such as groups, families, and sets, are not used to describe the horizontal rows but rather refer to different aspects of the periodic table organization. 'Groups' are the vertical columns, 'families' are groups of elements with similar properties, and 'sets' is a more generic term not specifically used in the context of the periodic table.

3. What charge do Group VIA elements typically have?

• A. -1
• B. -2
• C. -3
• D. 0

Correct answer: B

Rationale: Group VIA elements, also known as Group 16 elements, typically have a charge of -2. This is because they have 6 valence electrons and tend to gain 2 electrons to achieve a stable octet configuration, resulting in a -2 charge. Choice A (-1) is incorrect as Group VIA elements need to gain 2 electrons for stability, not just 1. Choice C (-3) is incorrect because Group VIA elements do not need to gain 3 electrons to achieve stability. Choice D (0) is incorrect as Group VIA elements need to gain electrons to reach a stable configuration, resulting in a negative charge.

4. Which substance is a product of photosynthesis?

• A. Carbon dioxide
• B. Oxygen
• C. Water
• D. Glucose

Correct answer: D

Rationale: During photosynthesis, plants and other organisms convert carbon dioxide and water into glucose and oxygen. Glucose is a carbohydrate produced by plants as a result of photosynthesis, serving as their main source of energy. Oxygen is released as a byproduct of this process, while carbon dioxide and water are the raw materials used to produce glucose. Therefore, the correct answer is 'Glucose,' making it a vital product of the photosynthesis process. Choices A, B, and C are incorrect as carbon dioxide and water are the reactants needed for photosynthesis, and oxygen is released as a byproduct.

5. How many electrons are shared in a single covalent bond?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The correct answer is B: '2'. In a single covalent bond, two electrons are shared between two atoms. Each atom contributes one electron to form the bond, resulting in the sharing of a total of two electrons. Choice A is incorrect because a single covalent bond involves the sharing of two electrons, not one. Choices C and D are incorrect as they do not represent the correct number of electrons shared in a single covalent bond.

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