Nursing Elites

1. In which state of matter are particles packed tightly together in a fixed position?

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

Correct answer: B

Rationale: In a 'solid' state, particles are tightly packed in fixed positions, maintaining a definite shape and volume. This arrangement allows solids to maintain a rigid structure. Liquids have particles that are close together but can move past each other, giving them the ability to flow and take the shape of their container. Gases have particles that are far apart and move freely, leading to their ability to expand to fill any container. Plasma is an ionized gas where particles have high energy levels and are not packed tightly together, making it an uncommon state of matter on Earth.

2. What term refers to the average of the masses of each of its isotopes as they occur in nature?

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

Correct answer: C

Rationale: The correct answer is atomic mass. Atomic mass is the weighted average of the masses of an element's isotopes. It takes into account the abundance of each isotope in nature to provide a more accurate representation of the element's overall mass. Choice A, atomic number, represents the number of protons in an atom. Choice B, mass number, refers to the total number of protons and neutrons in an atom's nucleus. Choice D, neutron number, specifically focuses on the count of neutrons in an atom's nucleus. These choices do not directly relate to the average mass of isotopes as asked in the question.

3. 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.

4. Arsenic and silicon are examples of ___________.

• A. metals
• B. nonmetals
• C. metalloids
• D. heavy metals

Correct answer: C

Rationale: Arsenic and silicon are both examples of metalloids. Metalloids have properties that lie between those of metals and nonmetals. They exhibit characteristics of both groups, making them versatile elements with various applications in different industries. Choice A (metals) is incorrect as arsenic and silicon do not exhibit typical metallic properties. Choice B (nonmetals) is incorrect as they do not possess all the properties of nonmetals. Choice D (heavy metals) is incorrect as heavy metals refer to a different group of elements with high atomic weights, and arsenic and silicon are not categorized as heavy metals.

5. Which factor does not affect the reaction rate of a chemical reaction?

• A. Temperature
• B. Surface area
• C. Concentration of reactants
• D. Color of the reactants

Correct answer: D

Rationale: The color of reactants is not a factor that affects the rate of a chemical reaction. Temperature, surface area, and concentration of reactants are known factors that influence the reaction rate. Temperature plays a significant role in altering the reaction rate by affecting the kinetic energy of molecules. Surface area impacts the rate by providing more area for collisions to occur. Concentration affects the frequency of effective collisions. On the other hand, the color of reactants is a physical property that does not directly affect the speed of a chemical reaction.

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