Nursing Elites

1. Positron emission tomography (PET) scans utilize a key property of positrons for medical imaging. What is this property?

• A. High mass
• B. Positive charge
• C. Extreme stability
• D. Identical behavior to electrons

Correct answer: B

Rationale: Positron emission tomography (PET) scans utilize the property of positrons having a positive charge. Positrons are the antimatter counterpart of electrons, having the same mass but opposite charge. When a positron collides with an electron, they annihilate each other, producing gamma rays that can be detected by the PET scanner to create images of the body's internal structures and functions. Choice A is incorrect because positrons have the same mass as electrons. Choice C is incorrect as positrons are not extremely stable due to their tendency to annihilate when they encounter electrons. Choice D is incorrect as positrons exhibit different behavior than electrons due to their opposite charges.

2. In the context of cholesterol levels, LDL cholesterol is often referred to as:

• A. HDL or "good" cholesterol.
• B. LDL or "bad" cholesterol.
• C. Total cholesterol, encompassing both LDL and HDL.
• D. VLDL, a type of triglyceride transported in the bloodstream.

Correct answer: B

Rationale: LDL cholesterol is often referred to as "bad" cholesterol because high levels of LDL can lead to plaque buildup in the arteries, increasing the risk of heart disease and stroke. LDL cholesterol is considered harmful as it contributes to the formation of plaque in blood vessels, whereas HDL cholesterol helps remove LDL from the arteries. Choice A is incorrect because HDL is known as "good" cholesterol, which helps remove LDL cholesterol from the bloodstream. Choice C is incorrect as it refers to total cholesterol, which includes LDL, HDL, and other lipids. Choice D is incorrect as VLDL is a different type of lipoprotein that carries triglycerides and is not specifically related to LDL cholesterol.

3. What is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy called?

• A. Nuclear fusion
• B. Nuclear fission
• C. Radioactive decay
• D. Chain reaction

Correct answer: B

Rationale: The correct answer is B: Nuclear fission. Nuclear fission is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy. This process is commonly used in nuclear power plants and nuclear weapons. It is a controlled chain reaction that generates energy. Option A, Nuclear fusion, is the process of combining two light nuclei to form a heavier nucleus, releasing energy. This process powers the sun and other stars. Option C, Radioactive decay, is the process by which an unstable atomic nucleus loses energy by emitting radiation. Option D, Chain reaction, is a self-sustaining reaction where the products of one reaction event stimulate further reaction events. While chain reactions can occur in both nuclear fission and fusion, the specific process of splitting a heavy nucleus into smaller ones is known as nuclear fission.

4. Which of the following describes an experiment?

• A. The final math grades for a group of students passing through each year of elementary school are examined.
• B. The health trends of smokers in a small random sample are examined.
• C. Citizens in a local community are surveyed to determine concerns related to the next election.
• D. The effects of a new drug are tested on a group of participants.

Correct answer: D

Rationale: Option D describes an experiment because it involves testing the effects of a new drug on a group of participants. In an experiment, researchers intentionally manipulate an independent variable (in this case, the new drug) to observe its effects on a dependent variable (the participants' health outcomes). This method allows for establishing cause-and-effect relationships between variables, which is a key characteristic of experimental research design. Choices A, B, and C do not represent experiments. Choice A involves observational analysis of math grades, choice B involves observational analysis of health trends, and choice C involves a survey, none of which involve manipulating variables to establish cause-and-effect relationships.

5. What is the difference between the atomic number and the mass number of an atom?

• A. The atomic number is the number of protons in the nucleus, while the mass number is the total number of protons and neutrons in the nucleus.
• B. The atomic number is the number of electrons in an atom, while the mass number is the total number of protons and neutrons in the nucleus.
• C. The atomic number is the number of neutrons in the nucleus, while the mass number is the total number of protons and electrons in an atom.
• D. The atomic number is the number of protons and neutrons in the nucleus, while the mass number is the total number of electrons in an atom.

Correct answer: A

Rationale: The atomic number of an atom represents the number of protons in its nucleus, which defines the element's identity. On the other hand, the mass number corresponds to the total sum of protons and neutrons in the nucleus. Therefore, the key distinction between the atomic number and the mass number lies in the fact that the atomic number specifically counts the protons, whereas the mass number encompasses both protons and neutrons. Choice B is incorrect because the atomic number is not related to the number of electrons but rather to the number of protons. Choice C is incorrect because the atomic number is not the number of neutrons but the number of protons. Choice D is incorrect because the atomic number does not include neutrons; it is solely the number of protons.

Similar Questions