Nursing Elites

1. What is atomic mass?

• A. Number of protons in an atom
• B. Sum of protons and neutrons
• C. Number of neutrons in an atom
• D. Average weight of an element

Correct answer: B

Rationale: Atomic mass, also known as atomic weight, is the sum of the number of protons and neutrons in an atom. It represents the average mass of an atom of an element, taking into account the different isotopes and their relative abundance. Neutrons contribute to the atomic mass alongside protons, while the number of neutrons alone is not the definition of atomic mass. Choice A is incorrect because it refers only to the number of protons, not the complete atomic mass. Choice C is incorrect as it focuses solely on the number of neutrons, excluding the contribution of protons. Choice D is incorrect as it mentions the 'average weight of an element,' which is related to atomic mass but does not encapsulate the specific definition of atomic mass as the sum of protons and neutrons.

2. What is the correct electron configuration for lithium?

• A. 1s²2s¹
• B. 1s²2s²
• C. 1s²2s¹2p¹
• D. 1s¹2s¹2p²

Correct answer: A

Rationale: The electron configuration for lithium is 1s²2s¹. Lithium has 3 electrons, and the configuration indicates that the first two electrons fill the 1s orbital, while the third electron fills the 2s orbital. Therefore, the correct electron configuration for lithium is 1s²2s¹. Choice B (1s²2s²) is incorrect as it represents the electron configuration for beryllium, not lithium. Choice C (1s²2s¹2p¹) includes the 2p orbital, which is not involved in lithium's electron configuration. Choice D (1s¹2s¹2p²) is incorrect as it does not accurately represent lithium's electron configuration.

3. Here are the solubilities of four substances at 0°C, in grams of solute per 100 mL of water. If the temperature increases to 20°C, what would you expect to happen to the solubility figures?

• A. Citric acid and potassium phosphate will decrease; nitrogen and oxygen will increase.
• B. Citric acid and potassium phosphate will increase; nitrogen and oxygen will decrease.
• C. All four figures will increase.
• D. All four figures will decrease.

Correct answer: C

Rationale: Solubility generally tends to increase with temperature for most solid solutes in liquid solvents due to higher kinetic energy leading to better solute-solvent interactions. As the temperature increases from 0°C to 20°C, all four solubility figures are expected to increase. Choice A is incorrect because solubility tends to increase with temperature. Choice B is incorrect as well for the same reason. Choice D is incorrect because the solubility of solid solutes typically increases with temperature.

4. Which chemical reaction involves the breaking of a compound into its components?

• A. Decomposition reaction
• B. Combustion reaction
• C. Neutralization reaction
• D. Single displacement reaction

Correct answer: A

Rationale: The correct answer is A: Decomposition reaction. A decomposition reaction involves breaking down a compound into its components. During this reaction, a single compound breaks down into two or more simpler substances. This process is the opposite of a synthesis reaction where multiple substances combine to form a more complex compound. Choices B, C, and D are incorrect because combustion reaction involves burning a substance in oxygen, neutralization reaction involves the reaction between an acid and a base to form water and a salt, and single displacement reaction involves an element displacing another in a compound.

5. What can stop the penetration of gamma radiation?

• A. Aluminum foil
• B. Glass
• C. Several feet of concrete
• D. Piece of paper

Correct answer: C

Rationale: Gamma radiation is highly penetrative and requires dense materials to block it effectively. While aluminum foil and glass are not sufficient to stop gamma radiation, several feet of concrete is needed due to its high density and ability to absorb gamma radiation effectively. A piece of paper is too thin and lacks the density required to block gamma radiation, making it an ineffective shield.

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