Nursing Elites

1. What is the basic structure of an atom?

• A. Protons, neutrons, electrons
• B. Protons, electrons, ions
• C. Neutrons, electrons, ions
• D. Protons, ions, molecules

Correct answer: A

Rationale: The basic structure of an atom consists of protons and neutrons located in the nucleus, with electrons orbiting around the nucleus in specific energy levels or shells. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. This arrangement maintains the overall neutrality of the atom, with the number of protons equaling the number of electrons. Therefore, the correct answer is 'Protons, neutrons, electrons.' Choices B, C, and D are incorrect as they do not accurately represent the fundamental components of an atom. Choice B includes 'ions,' which are charged particles, not fundamental components of an atom. Choice C includes 'ions' and lacks protons. Choice D includes 'ions' and 'molecules,' which are not part of the basic structure of an atom.

2. What is the purpose of a catalyst?

• A. To increase a reaction rate by increasing the activation energy
• B. To increase a reaction rate by increasing the temperature
• C. To increase a reaction rate by decreasing the activation energy
• D. To increase a reaction rate by decreasing the temperature

Correct answer: C

Rationale: The purpose of a catalyst is to increase a reaction's rate by decreasing the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly without being consumed in the process. The catalyst provides an alternate mechanism with a lower activation energy, making it easier for the reactants to convert into products. Choice A is incorrect because a catalyst lowers, not increases, the activation energy. Choice B is incorrect because a catalyst does not affect the temperature directly but provides an alternative pathway for the reaction to occur more easily. Choice D is incorrect because a catalyst does not lower the temperature but facilitates the reaction by lowering the activation energy barrier. Therefore, the correct answer is C, 'To increase a reaction rate by decreasing the activation energy.'

3. How many moles of water are produced when 0.5 moles of methane (CH4) react with excess oxygen?

• A. 0.5 moles
• B. 1 mole
• C. 2 moles
• D. 3 moles

Correct answer: B

Rationale: The balanced chemical equation for the combustion of methane is: CH4 + 2O2 -> CO2 + 2H2O. This equation shows that 1 mole of methane produces 2 moles of water. Therefore, when 0.5 moles of methane react, they will produce 1 mole of water. The ratio of water to methane is 2:1, meaning that for every mole of methane that reacts, it produces 2 moles of water. Since only 0.5 moles of methane are reacting, the amount of water produced will be half of what would be produced if 1 mole of methane reacted, resulting in 1 mole of water being produced. Choice A is incorrect because it does not consider the stoichiometry of the reaction. Choices C and D are incorrect as they do not align with the balanced chemical equation and the stoichiometric ratios involved in the reaction.

4. Muscle tissues often require quick bursts of energy. As a result, which of the following organelles would be most likely to be found in higher than normal amounts in muscle cells?

• A. ribosomes
• B. chloroplasts
• C. vacuoles
• D. mitochondria

Correct answer: D

Rationale: Muscle tissues require quick bursts of energy for activities such as contraction and relaxation. Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP through cellular respiration. Therefore, muscle cells would require higher amounts of mitochondria to meet their energy demands. Ribosomes are involved in protein synthesis and are not directly related to energy production. Chloroplasts are found in plant cells and are responsible for photosynthesis, not in animal muscle cells. Vacuoles are primarily involved in storage, maintaining turgor pressure, and digestion, but they are not the main organelles involved in energy production.

5. Which of the following is a chief difference between evaporation and boiling?

• A. Liquids boil only at the surface, while they evaporate equally throughout the liquid.
• B. Evaporating substances change from liquid to gas, while boiling substances change from gas to liquid.
• C. Evaporation can happen below a liquid's boiling point.
• D. Evaporation happens in nature, while boiling is a man-made phenomenon.

Correct answer: C

Rationale: The chief difference between evaporation and boiling is that evaporation can happen below a liquid's boiling point, while boiling only occurs at the liquid's boiling point. Evaporation is the process of a liquid turning into a gas at any temperature, while boiling specifically refers to the rapid vaporization that occurs when a liquid reaches its boiling point. Choice A is incorrect because liquids evaporate throughout the liquid, not just at the surface. Choice B is incorrect as evaporating substances change from liquid to gas, while boiling substances change from liquid to gas. Choice C is incorrect as boiling is not a man-made phenomenon; in fact, it is a natural process based on temperature changes. Choice D is incorrect because evaporation can happen naturally and is not limited to man-made processes.

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