Nursing Elites

1. How does kinetic energy change when the velocity of an object is doubled?

• A. Kinetic energy is halved
• B. Kinetic energy quadruples
• C. Kinetic energy doubles
• D. Kinetic energy remains the same

Correct answer: b

Rationale: Kinetic energy is directly proportional to the square of the velocity of an object.

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

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

Correct answer: A

Rationale: Rationale: - Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule. This composition does not vary. - Mixtures, on the other hand, 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. - Option A correctly distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures.

3. What is the term for a substance that can act as both a proton donor and a proton acceptor?

• A. Acid
• B. Base
• C. Amphiprotic
• D. Neutral

Correct answer: C

Rationale: Amphiprotic substances can act as both a proton donor and a proton acceptor. The other choices are specific to either acids or bases.

4. Rectangle: A picture frame measures 15cm by 20cm. What is its perimeter?

• A. 30cm
• B. 55cm
• C. 65cm
• D. 75cm

Correct answer: C

Rationale: Add the lengths of all sides: perimeter = 2 (length + width) = 2 (15cm + 20cm) = 65cm.

5. Glands that release hormones directly into the bloodstream without ducts are called:

• A. Exocrine glands
• B. Endocrine glands
• C. Apocrine glands
• D. Merocrine glands

Correct answer: B

Rationale: The correct answer is B: Endocrine glands. Endocrine glands are specialized glands that release hormones directly into the bloodstream, which then travel to target organs or tissues to regulate various physiological processes. Unlike exocrine glands (choice A), which secrete their products through ducts to specific locations, endocrine glands secrete hormones into the blood for more widespread and systemic effects. Apocrine glands (choice C) release a portion of their cell contents along with the secretions, while merocrine glands (choice D) release their products through exocytosis without any loss of cell material. Therefore, in this case, endocrine glands best describe the glands that release hormones directly into the bloodstream without ducts.

6. What type of reaction is represented by the following equation: Fe2O3 (s) + 3H2 (g) -> 2Fe (s) + 3H2O (g)

• A. Combustion
• B. Decomposition
• C. Single displacement
• D. Redox reaction

Correct answer: D

Rationale: The given equation involves a transfer of electrons from iron oxide (Fe2O3) to hydrogen gas (H2), resulting in the formation of iron (Fe) and water (H2O). This transfer of electrons indicates a redox reaction, where oxidation and reduction occur simultaneously. In this case, iron is reduced from a higher oxidation state in Fe2O3 to a lower oxidation state in Fe, while hydrogen is oxidized from its elemental state in H2 to form water. Therefore, the correct answer is D: Redox reaction.

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