Nursing Elites

1. What number represents the number of protons an element has?

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

Correct answer: C

Rationale: The correct answer is C, atomic number. The atomic number corresponds to the number of protons in an element. This number is unique to each element and determines its placement on the periodic table. It is equal to the number of protons found in the nucleus of an atom of that element. Choice A, atomic mass, represents the average mass of an element's isotopes. Choice B, mass number, is the sum of protons and neutrons in an atom. Choice D, neutron number, specifically refers to the count of neutrons in an atom and not protons.

2. What is the oxidation state of the potassium ion in the compound KCl?

• A. +1
• B. -1
• C. +2
• D. -2

Correct answer: A

Rationale: In the compound KCl (potassium chloride), potassium is in Group 1 of the periodic table, which means it has a valence electron of 1. Chlorine is in Group 17 and gains one electron to achieve a stable electron configuration by forming an ionic bond with potassium. As a result, the potassium ion in KCl has a +1 oxidation state. Therefore, the correct answer is +1. Choices B, C, and D are incorrect as they do not reflect the oxidation state of the potassium ion in KCl.

3. What are negatively charged ions called?

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

Correct answer: C

Rationale: Negatively charged ions are called anions. Anions gain electrons and carry a negative charge, which distinguishes them from cations that are positively charged and neutrons and protons that are subatomic particles found in the nucleus of an atom. Choice A, Neutrons, are neutral subatomic particles found in the nucleus of an atom, not negatively charged ions. Choice B, Protons, are positively charged subatomic particles found in the nucleus of an atom, not negatively charged ions. Choice D, Cations, are positively charged ions that lose electrons, which is opposite to the behavior of negatively charged ions.

4. What are mixtures of 2 or more metals called?

• A. Solutions
• B. Alloys
• C. Compounds
• D. Suspensions

Correct answer: B

Rationale: Alloys are mixtures of two or more metals, combining their properties to create materials with enhanced characteristics. Examples of alloys include bronze (copper and tin) and steel (iron and carbon). Alloys are commonly used in various industries due to their improved strength, durability, and other desirable qualities. Solutions (Choice A) refer to a homogeneous mixture of two or more substances, where one substance is dissolved in another. Compounds (Choice C) are substances composed of two or more elements chemically combined in fixed proportions. Suspensions (Choice D) are heterogeneous mixtures where particles are dispersed but can settle out over time.

5. Why does the diffusion rate increase as a substance is heated?

• A. The kinetic energy of particles increases.
• B. The space between particles increases.
• C. The density of particles decreases.
• D. The size of particles increases.

Correct answer: A

Rationale: The correct answer is A. When a substance is heated, the kinetic energy of particles increases, causing them to move faster. This increased movement allows the particles to spread out more rapidly, leading to a higher diffusion rate. Choice B is incorrect because heating does not directly affect the space between particles. Choice C is incorrect because heating does not necessarily lead to a decrease in the density of particles. Choice D is incorrect because the size of particles does not necessarily increase when a substance is heated. Therefore, the correct explanation for the increase in diffusion rate is the rise in kinetic energy of particles.

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