Nursing Elites

1. 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.

2. Which state of matter has a definite volume but takes the shape of its container?

• A. Gas
• B. Liquid
• C. Solid
• D. Plasma

Correct answer: B

Rationale: The state of matter that has a definite volume but takes the shape of its container is a 'Liquid.' Liquids have a fixed volume but can change their shape to fit the container they are in. This property distinguishes liquids from solids, which have both a definite shape and volume, and gases, which do not have a fixed volume or shape. Therefore, the correct answer is 'Liquid.' Choice A, 'Gas,' is incorrect because gases do not have a definite volume or shape. Choice C, 'Solid,' is incorrect as solids have a definite shape and volume. Choice D, 'Plasma,' is incorrect because plasma is a state of matter where atoms have been ionized and do not have a fixed volume or shape.

3. Which intermolecular force is the strongest?

• A. Dipole interactions
• B. Dispersion forces
• C. Hydrogen bonding
• D. Van der Waals forces

Correct answer: C

Rationale: Hydrogen bonding is the strongest intermolecular force due to its specific interaction between a hydrogen atom and a highly electronegative atom like nitrogen, oxygen, or fluorine. This type of bonding results in a very strong attraction between molecules, making it the strongest intermolecular force among the options provided. Dipole interactions (choice A) are weaker than hydrogen bonding as they occur between polar molecules. Dispersion forces (choice B) are the weakest intermolecular forces and are caused by temporary fluctuations in electron distribution. Van der Waals forces (choice D) are a broader term that encompasses dipole interactions and dispersion forces, making them weaker than hydrogen bonding.

4. What does the term amphoteric mean?

• A. A substance that only acts as a base
• B. A substance that can act as both a base and an acid
• C. A substance that only acts as an acid
• D. A substance that acts as neither a base nor an acid

Correct answer: B

Rationale: The term 'amphoteric' refers to substances that have the ability to act as both acids and bases depending on the surrounding conditions. This dual nature allows amphoteric substances to donate or accept protons, making them versatile in various chemical reactions. Choice A is incorrect because amphoteric substances can also act as acids. Choice C is incorrect as amphoteric substances can also act as bases. Choice D is incorrect as amphoteric substances can act as either a base or an acid.

5. What is the oxidation state of the nitrogen atom in the compound NH3?

• A. -3
• B. -1
• C. +1
• D. +3

Correct answer: B

Rationale: In the compound NH3, nitrogen is bonded to three hydrogen atoms. Hydrogen is always assigned an oxidation state of +1. Since the overall charge of NH3 is zero, the oxidation state of nitrogen must be -1 to balance out the hydrogen's +1 oxidation state. Therefore, the correct oxidation state of the nitrogen atom in NH3 is -1. Choice A (-3) is incorrect because it does not account for the electronegativity of hydrogen. Choice C (+1) and Choice D (+3) are incorrect as the nitrogen atom in NH3 needs to balance the +1 oxidation state of each hydrogen atom, resulting in a total of -3 to maintain the compound's charge neutrality.

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