Nursing Elites

1. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

• A. Na
• B. H2O
• C. NaOH
• D. H2

Correct answer: a

Rationale: Sodium is the limiting reactant because it runs out first in a 1:1 ratio with water.

2. Action potentials, the all-or-nothing electrical signals traveling along neurons, are generated by the movement of:

• A. Glucose
• B. Sodium and potassium ions
• C. Neurotransmitters
• D. Myelin

Correct answer: B

Rationale: The correct answer is B: Sodium and potassium ions. Action potentials are generated by the movement of sodium and potassium ions across the neuronal membrane. During depolarization, sodium ions rush into the cell, causing a change in electrical charge. This influx of positive ions triggers the opening of voltage-gated potassium channels, allowing potassium ions to exit the cell during repolarization. Glucose is a source of energy for cells but does not directly generate action potentials. Neurotransmitters are chemical messengers released at synapses, while myelin is a fatty substance that insulates axons, speeding up the conduction of action potentials but not directly generating them.

3. What property of a substance remains constant regardless of changes in its shape or size?

• A. Mass
• B. Weight
• C. Density
• D. Volume

Correct answer: a

Rationale: Mass remains constant regardless of changes in an object's shape or size.

4. Which word in the sentence "The quick brown fox jumps over the lazy dog" demonstrates alliteration?

• A. quick
• B. brown
• C. fox
• D. jumps

Correct answer: A

Rationale: Alliteration is the repetition of the first consonant sound of words close together. In this case, "quick" and "brown" both start with the "k" sound.

5. The passage implies that achieving energy sustainability requires...

• A. solely relying on renewable energy sources for electricity generation.
• B. a combination of advancements in renewable energy production and management technologies.
• C. prioritizing economic benefits over environmental concerns when making energy choices.
• D. focusing solely on reducing energy consumption without addressing production sources.

Correct answer: B

Rationale: The passage emphasizes the need for both increasing renewable energy and managing its fluctuations, suggesting B as the key to sustainability.

6. A balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is:

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: A

Rationale: The correct balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is '2Na + Cl2 -> 2NaCl'. This equation is balanced as it shows that 2 atoms of sodium react with 1 molecule of chlorine gas to produce 2 molecules of sodium chloride. Option A 'Na + Cl2 -> NaCl' is incorrect as it does not balance the number of atoms on both sides of the equation. It only shows 1 atom of sodium reacting with 1 molecule of chlorine, which is not a balanced representation of the chemical reaction. Therefore, option B is the correct choice for this question.

Similar Questions