Nursing Elites

1. Which of the following statements is true about Noble gases?

• A. They are non-reactive.
• B. They are highly reactive.
• C. They have 8 valence electrons.
• D. They have 7 valence electrons.

Correct answer: A

Rationale: The correct answer is A: Noble gases are non-reactive because they have a full valence shell with 8 electrons, making them stable and unlikely to form chemical bonds with other elements. Choice B is incorrect because Noble gases are known for their inertness and lack of reactivity. Choice C is incorrect because Noble gases have 8 valence electrons, which is a key characteristic that contributes to their stability. Choice D is incorrect because Noble gases have 8 valence electrons, not 7.

2. How many neutrons are in an atom of the following element with a mass number of 50?

• A. 38
• B. 88
• C. 50
• D. 126

Correct answer: C

Rationale: Neutrons are found in the nucleus of an atom along with protons. To determine the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number. In this case, the mass number given is 50. Since the atomic number is not specified, we can infer it from the choices provided. The mass number of an element represents the total sum of protons and neutrons in the nucleus. Therefore, the number of neutrons in this atom would also be 50, as the mass number is equivalent to the combined number of protons and neutrons, making choice C the correct answer. Choices A, B, and D are incorrect as they do not match the given mass number of 50.

3. What property of a substance refers to its ability to be drawn into thin wires?

• A. Conductivity
• B. Ductility
• C. Viscosity
• D. Malleability

Correct answer: B

Rationale: Ductility is the property of a substance that allows it to be drawn into thin wires without breaking. Conductivity refers to the ability of a substance to conduct electricity or heat, not to be drawn into wires. Viscosity is the measure of a fluid's resistance to flow, not related to the ability to be drawn into wires. Malleability is the property of a substance that allows it to be hammered or rolled into thin sheets, not specifically related to being drawn into wires. Therefore, the correct property for the ability to be drawn into thin wires is ductility.

4. What is the valve that prevents blood from flowing back from the left ventricle into the left atrium?

• A. Tricuspid valve
• B. Mitral valve
• C. Aortic valve
• D. Pulmonic valve

Correct answer: B

Rationale: The correct answer is the Mitral valve. The mitral valve is located between the left atrium and the left ventricle of the heart. Its function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. Choice A, the Tricuspid valve, is incorrect as it is located between the right atrium and right ventricle. Choice C, the Aortic valve, and Choice D, the Pulmonic valve, are also incorrect as they are involved in the circulation of blood leaving the heart rather than preventing backflow within the atria and ventricles.

5. Which hormone deficiency can lead to stunted growth and developmental delays in children?

• A. Estrogen
• B. Testosterone
• C. Growth hormone
• D. Insulin

Correct answer: C

Rationale: The correct answer is C, Growth hormone. Growth hormone plays a crucial role in stimulating growth, cell reproduction, and regeneration in children. A deficiency in growth hormone can lead to stunted growth and developmental delays. Estrogen and testosterone are sex hormones that do not directly influence growth in the same way as growth hormone. Insulin primarily regulates blood sugar levels and is not the primary hormone responsible for growth and development in children.

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