Nursing Elites

1. What is the name of the phase change from liquid to gas?

• A. Condensation
• B. Sublimation
• C. Evaporation
• D. Melting

Correct answer: C

Rationale: The correct answer is 'Evaporation.' This phase change occurs when a liquid turns into a gas. During evaporation, molecules gain enough energy to break free from the liquid phase and enter the gas phase, without the need for the liquid to reach its boiling point. Choice A, 'Condensation,' is the opposite phase change where gas turns into a liquid. Choice B, 'Sublimation,' is the phase change from solid directly to gas, skipping the liquid phase. Choice D, 'Melting,' is the phase change from solid to liquid.

2. What is the correct name of AgNO₃?

• A. Argent nitrous
• B. Argent oxide
• C. Silver nitrite
• D. Silver nitrate

Correct answer: D

Rationale: The correct name for AgNO₃ is silver nitrate. In chemical nomenclature, the element symbol Ag represents silver, and the polyatomic ion NO₃ is known as nitrate. Therefore, when the silver ion (Ag⁺) combines with the nitrate ion (NO₃⁻), the resulting compound is named silver nitrate (AgNO₃). Choices A, B, and C are incorrect because they do not accurately represent the composition of AgNO₃. Argent nitrous (Choice A) and Argent oxide (Choice B) do not reflect the correct anion, and Silver nitrite (Choice C) uses a different anion altogether.

3. Which of the following represents a hydride ion?

• A. H⁻
• B. H⁺
• C. OH⁻
• D. HCl

Correct answer: A

Rationale: The hydride ion is denoted by H⁻, indicating that it has gained an extra electron to complete its valence shell, resulting in a full octet and a net charge of -1. This ion is commonly found in metal hydrides and plays a significant role in various chemical reactions. Option B, H⁺, represents a proton with a positive charge. Option C, OH⁻, represents the hydroxide ion, consisting of oxygen and hydrogen. Option D, HCl, is a compound composed of hydrogen and chlorine ions, not a hydride ion.

4. What are the columns of the periodic table called?

• A. Periods
• B. Families
• C. Groups
• D. Rows

Correct answer: C

Rationale: In the periodic table, columns are referred to as groups, not periods, families, or rows. These groups share similar chemical properties due to the arrangement of elements within each group, which is based on the number of valence electrons. The vertical columns help classify elements with similar characteristics. Periods refer to the rows of the periodic table, while families or groups are the vertical columns.

5. What are positively charged ions called?

• A. Neutrons
• B. Protons
• C. Cations
• D. Electrons

Correct answer: C

Rationale: Positively charged ions are called cations. When an atom loses electrons, it becomes positively charged and is referred to as a cation. Neutrons are neutral particles found in the nucleus of an atom, not charged. Protons are positively charged particles in the nucleus. Electrons are negatively charged particles orbiting the nucleus, not positively charged ions.

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