Nursing Elites

1. What is the main function of the lungs?

• A. To transport oxygen and nutrients throughout the body
• B. To coordinate movement and sensory information
• C. To filter waste products from the blood
• D. To exchange oxygen and carbon dioxide between the body and the environment

Correct answer: D

Rationale: The main function of the lungs is to exchange oxygen and carbon dioxide between the body and the environment. This process occurs through the alveoli in the lungs where oxygen from inhaled air enters the bloodstream, and carbon dioxide is removed from the bloodstream and exhaled. Option A is incorrect as the transportation of oxygen and nutrients throughout the body is primarily carried out by the circulatory system, not the lungs. Option B is incorrect as coordinating movement and sensory information is a function of the nervous system, not the lungs. Option C is incorrect as filtering waste products from the blood is primarily the role of the kidneys, not the lungs. Therefore, the correct answer is D.

2. What is the term for the tiny particles that make up atoms?

• A. Protons
• B. Electrons
• C. Neutrons
• D. Subatomic particles

Correct answer: D

Rationale: The correct answer is 'Subatomic particles.' Subatomic particles are the tiny components that constitute atoms, including protons, neutrons, and electrons. Protons and neutrons are located in the nucleus of an atom, while electrons revolve around the nucleus. Choices A, B, and C specifically refer to individual subatomic particles but do not encompass the complete range of particles within an atom.

3. What is the difference between a pure substance and a mixture?

• A. Pure substances have a fixed composition, mixtures don't.
• B. Mixtures have a fixed composition, pure substances don't.
• C. Pure substances can be in any state, mixtures are not always solids.
• D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

4. Imagine you have an element with atomic number 20 and mass number 40. How many neutrons does it have?

• A. 20
• B. 40
• C. 10
• D. 20

Correct answer: C

Rationale: - The atomic number (Z) represents the number of protons in an atom. In this case, the atomic number is 20. - The mass number (A) represents the total number of protons and neutrons in an atom. In this case, the mass number is 40. - To find the number of neutrons, you subtract the atomic number from the mass number: Neutrons = Mass number - Atomic number. - Neutrons = 40 - 20 = 20. - Therefore, the element with atomic number 20 and mass number 40 has 20 neutrons.

5. Which of the following macromolecules will always contain nitrogen?

• A. Fatty acids
• B. Proteins
• C. Lipids
• D. Carbohydrates

Correct answer: B

Rationale: The correct answer is B: Proteins. Proteins are the only macromolecules that always contain nitrogen in their amino acid structure. Nitrogen is a key element found in the amino groups of amino acids, which are the building blocks of proteins. Fatty acids (Choice A), lipids (Choice C), and carbohydrates (Choice D) do not always contain nitrogen in their structure. Fatty acids are composed of long hydrocarbon chains and do not contain nitrogen. Lipids consist mainly of carbon, hydrogen, and oxygen, with some classes of lipids containing phosphorus but not nitrogen. Carbohydrates are made up of carbon, hydrogen, and oxygen, forming structures like sugars and starches, but they do not contain nitrogen.

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