Nursing Elites

1. Isotopes are variants of a single element that differ in:

• A. Having the same number of protons but varying numbers of neutrons
• B. Having the same number of neutrons but varying numbers of protons
• C. Having the same mass but different atomic numbers
• D. None of the above

Correct answer: A

Rationale: Isotopes are variants of a single element that have the same number of protons, the defining characteristic of an element. They differ in the number of neutrons they possess, leading to isotopes having different atomic masses while retaining the same chemical properties. Choice B is incorrect because isotopes have the same number of neutrons and differ in the number of protons. Choice C is incorrect because isotopes have different masses due to varying numbers of neutrons, not different atomic numbers. Choice D is incorrect as isotopes do differ in the number of neutrons they possess.

2. What information can be obtained from the mass number of an element?

• A. The number of protons in the nucleus
• B. The total number of protons and neutrons
• C. The number of electrons in the valence shell
• D. The element's chemical reactivity

Correct answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in the nucleus. This information is crucial for determining the atomic mass of the element and understanding its stability and isotopes. The number of protons in the nucleus (option A) is represented by the atomic number, not the mass number. The number of electrons in the valence shell (option C) is related to the element's position in the periodic table and its chemical properties, but it is not directly determined by the mass number. The element's chemical reactivity (option D) is influenced by the number and arrangement of electrons in the atom's energy levels, not by the mass number.

3. Imagine you have an element with atomic number 11 and mass number 23. How many neutrons does it have?

• A. 11
• B. 12
• C. 23
• D. 21

Correct answer: B

Rationale: - The atomic number (Z) of an element is the number of protons in its nucleus. In this case, the element has an atomic number of 11. - The mass number (A) of an element is the sum of its protons and neutrons. Given that the mass number is 23 and the atomic number is 11, we can calculate the number of neutrons by subtracting the atomic number from the mass number: Neutrons = Mass number - Atomic number = 23 - 11 = 12. - Therefore, the element with atomic number 11 and mass number 23 has 12 neutrons.

4. How does sunscreen protect the skin from harmful ultraviolet (UV) rays?

• A. By reflecting UV rays away from the skin
• B. By absorbing UV rays and converting them to heat
• C. By blocking UV rays completely
• D. By stimulating melanin production

Correct answer: B

Rationale: Sunscreen works by absorbing UV rays and converting them to heat. This mechanism helps to prevent the UV rays from penetrating the skin and causing damage such as sunburn, premature aging, and skin cancer. Reflecting UV rays away from the skin (option A) is not the primary function of sunscreen. While sunscreen does block UV rays, it does not do so completely (option C) as some UV rays may still penetrate the skin. Sunscreen does not stimulate melanin production (option D) as a means of protecting the skin from UV rays.

5. Which part of the heart receives oxygenated blood from the lungs?

• A. Left atrium
• B. Right atrium
• C. Left ventricle
• D. Right ventricle

Correct answer: A

Rationale: The correct answer is A, the left atrium. The left atrium receives oxygenated blood from the lungs, which is then pumped into the left ventricle and out to the rest of the body. The right atrium receives deoxygenated blood from the body and sends it to the right ventricle to be pumped to the lungs for oxygenation. Choices B, C, and D are incorrect as they do not directly receive oxygenated blood from the lungs.

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