Nursing Elites

1. What do isotopes of the same element have in common?

• A. Identical number of protons and neutrons.
• B. Identical chemical properties.
• C. Identical number of electrons.
• D. Identical mass number.

Correct answer: D

Rationale: Isotopes of the same element have the same number of protons, which defines the element, but different numbers of neutrons. This difference in neutron count results in isotopes of the same element having different mass numbers. Chemical properties are determined by the arrangement of electrons in an atom, so isotopes of the same element may exhibit slightly different chemical behaviors due to different neutron numbers. The number of electrons can vary in isotopes, affecting their charge. However, the mass number, which is the sum of protons and neutrons, is the same for isotopes of the same element. Therefore, the correct answer is that isotopes of the same element share an identical mass number.

2. Which of the following infectious diseases can be caused by a protozoan parasite?

• A. Measles
• B. Malaria
• C. Mumps
• D. Mononucleosis

Correct answer: B

Rationale: The correct answer is B: Malaria. Malaria is caused by Plasmodium, a protozoan parasite transmitted through the bite of infected mosquitoes. Measles and mumps are viral diseases caused by separate viruses. Mononucleosis, on the other hand, is caused by the Epstein-Barr virus, which is also a viral infection. Therefore, choices A, C, and D are incorrect as they are caused by viruses, not protozoa.

3. When you push a book across a table, the book experiences an equal and opposite force from the table. Why doesn't the table move as well?

• A. The table is much heavier than the book.
• B. The force on the book acts in a different direction.
• C. The table has a much larger surface area, distributing the force over a wider area.
• D. All of the above

Correct answer: A

Rationale: The table is much heavier than the book, so it requires a much larger force to accelerate it. The book is lighter and easier to move, so the force applied to it causes it to move without significantly affecting the table due to the table's greater mass. Newton's third law states that for every action, there is an equal and opposite reaction. In this case, the force exerted on the book by the table is countered by an equal force exerted on the table by the book, but the table's greater mass resists movement. Choice B is incorrect because the forces are equal and opposite, acting in the same direction. Choice C is incorrect as the surface area does not affect the movement of the table in this scenario. Therefore, the correct answer is A, as the table's greater mass prevents it from moving easily when a force is applied.

4. Where does gas exchange take place in the respiratory system?

• A. Alveoli
• B. Bronchioles
• C. Bronchi
• D. Trachea

Correct answer: A

Rationale: Gas exchange in the respiratory system occurs in the alveoli, which are tiny air sacs in the lungs. Within the alveoli, oxygen from the inhaled air diffuses into the bloodstream, while carbon dioxide from the blood enters the alveoli to be exhaled. This exchange of gases is essential for the body to obtain oxygen and remove carbon dioxide, supporting vital bodily functions. The bronchioles (choice B), bronchi (choice C), and trachea (choice D) are part of the airway passage system that transports air to and from the alveoli but do not participate in gas exchange. Therefore, the alveoli play a crucial role in the respiratory system by facilitating gas exchange.

5. 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: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.

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