Nursing Elites

1. Which number represents the number of protons in an element?

• A. Atomic mass
• B. Mass number
• C. Atomic number
• D. Proton number

Correct answer: C

Rationale: The correct answer is C: Atomic number. The atomic number corresponds to the number of protons in an element. Protons are positively charged subatomic particles found in the nucleus of an atom. Each element has a unique atomic number, which defines its identity based on the number of protons it contains. Choice A, Atomic mass, is incorrect as it refers to the average mass of an atom of an element. Choice B, Mass number, represents the total number of protons and neutrons in an atom's nucleus. Choice D, Proton number, is not a commonly used term in chemistry to indicate the number of protons.

2. Which substance has a pH value greater than 7?

• A. Water
• B. Vinegar
• C. Lemon juice
• D. Baking soda

Correct answer: D

Rationale: The correct answer is D, Baking soda. Baking soda has a pH greater than 7, making it basic. pH values above 7 indicate alkalinity, and baking soda, being a base, has a pH higher than 7. Water, vinegar, and lemon juice have pH values below 7, indicating acidity. Water is neutral with a pH of 7, while vinegar and lemon juice are acidic with pH values lower than 7.

3. Which is a property of an ionic compound?

• A. Low melting point
• B. Poor conductivity
• C. Shared electrons
• D. Crystalline shape

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.

4. Which of these types of intermolecular force is the strongest?

• A. Dipole-dipole interaction
• B. London dispersion force
• C. Keesom interaction
• D. Hydrogen bonding

Correct answer: D

Rationale: Hydrogen bonding is the strongest type of intermolecular force among the options provided. It occurs when a hydrogen atom is covalently bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and forms a strong electrostatic attraction with an unshared pair of electrons on another electronegative atom. This type of bond is stronger than dipole-dipole interactions, London dispersion forces, and Keesom interactions due to the significant electronegativity difference between the hydrogen and the electronegative atom involved in the bond. The presence of hydrogen bonding contributes to unique properties in substances, such as high boiling and melting points, making it a crucial force in various biological and chemical processes.

5. What is a pentose sugar?

• A. A 6 carbon sugar
• B. A 4 carbon sugar
• C. A 5 carbon sugar
• D. A 7 carbon sugar

Correct answer: C

Rationale: A pentose is a 5-carbon sugar, as the prefix 'pent-' signifies five. Therefore, a pentose sugar consists of five carbon atoms. Choice A, 'A 6 carbon sugar,' is incorrect as a pentose sugar specifically has five carbons. Choice B, 'A 4 carbon sugar,' is incorrect as it describes a tetrose sugar, which has four carbons. Choice D, 'A 7 carbon sugar,' is incorrect as it does not correspond to the definition of a pentose sugar.

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