Nursing Elites

1. The number of protons in an atom determines its:

• A. Mass number
• B. Atomic number
• C. Atomic weight
• D. Valence electron count

Correct answer: B

Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.

2. Which of the following represents the three main parts of a neuron?

• A. effector, cell body, axon
• B. dendrites, axon, cell body
• C. dendrites, axon, receptor
• D. synapse, axon, cell body

Correct answer: B

Rationale: A neuron consists of three main parts: dendrites, axon, and cell body. Dendrites receive signals from other neurons or sensory receptors. The cell body (soma) contains the nucleus and organelles essential for neuron function. The axon transmits electrical impulses away from the cell body to other neurons, muscles, or glands. Choice A is incorrect because an effector is not a part of a neuron. Choice C is incorrect because a receptor is not a component of a neuron but rather interacts with neurons. Choice D is incorrect because the synapse is a junction between neurons for signal transmission, not a structural part of a neuron.

3. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

4. What is the name for the smallest amount of an element that can exist independently and retain its chemical properties?

• A. Atom
• B. Molecule
• C. Compound
• D. Mixture

Correct answer: A

Rationale: The correct answer is 'Atom.' An atom is the fundamental unit of an element that can exist independently and retain its unique chemical properties. It consists of a nucleus containing protons and neutrons, surrounded by electrons. Choice B, 'Molecule,' is incorrect because a molecule is a combination of two or more atoms bonded together. Choice C, 'Compound,' is incorrect as a compound is a substance formed by the chemical combination of two or more different elements. Choice D, 'Mixture,' is incorrect since a mixture is a blend of two or more substances physically combined, but the individual components retain their properties.

5. In which units is the speed of light in a vacuum measured?

• A. Meters per second
• B. Hertz
• C. Candela
• D. Newton

Correct answer: A

Rationale: The speed of light in a vacuum is commonly measured in units of meters per second. This is because the speed of light is approximately 299,792,458 meters per second in a vacuum, as defined by the International System of Units (SI). The speed of light is a measure of distance covered by light in a given time, hence it is expressed in meters per second. Choices B, C, and D are incorrect. Hertz is a unit of frequency, Candela is a unit of luminous intensity, and Newton is a unit of force. None of these units are relevant for measuring the speed of light, making 'Meters per second' the correct unit of measurement for the speed of light.

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