Nursing Elites

1. What term refers to the average of the masses of each of its isotopes as they occur in nature?

• A. Atomic number
• B. Mass number
• C. Atomic mass
• D. Neutron number

Correct answer: C

Rationale: The correct answer is atomic mass. Atomic mass is the weighted average of the masses of an element's isotopes. It takes into account the abundance of each isotope in nature to provide a more accurate representation of the element's overall mass. Choice A, atomic number, represents the number of protons in an atom. Choice B, mass number, refers to the total number of protons and neutrons in an atom's nucleus. Choice D, neutron number, specifically focuses on the count of neutrons in an atom's nucleus. These choices do not directly relate to the average mass of isotopes as asked in the question.

2. What are the two types of chemical bonding?

• A. Covalent & hydrogen
• B. Ionic & covalent
• C. Ionic & hydrogen
• D. Covalent & metallic

Correct answer: B

Rationale: The correct answer is B: Ionic & covalent. Ionic bonding involves the transfer of electrons between atoms, resulting in the formation of positive and negative ions attracted to each other. Covalent bonding involves the sharing of electrons between atoms to achieve a stable electron configuration. Choice A is incorrect as hydrogen bonding is a type of intermolecular force, not a primary type of chemical bonding. Choice C is incorrect as hydrogen bonding is not a primary type of chemical bonding. Choice D is incorrect as metallic bonding involves the sharing of electrons in a 'sea of electrons' within a metal lattice, not covalent bonding.

3. Which type of radiation emits helium ions and can be stopped by a piece of paper?

• A. Beta radiation
• B. Alpha radiation
• C. Gamma radiation
• D. X-ray radiation

Correct answer: B

Rationale: Alpha radiation emits helium ions, which are helium nuclei without electrons, making them positively charged. These ions are relatively large and heavy compared to beta and gamma radiation. Due to their size and charge, alpha particles interact strongly with matter and are easily stopped. A piece of paper or even human skin can effectively block alpha radiation. Therefore, alpha radiation is the type of radiation that can be stopped by a piece of paper. Beta radiation consists of fast-moving electrons and can penetrate further into materials than alpha radiation, thus not stopped by a piece of paper. Gamma radiation is highly penetrating and requires dense materials like lead or concrete to block it effectively. X-ray radiation, similar to gamma radiation, is also highly penetrating and cannot be stopped by a piece of paper.

4. What type of bond is an electrostatic attraction between two oppositely charged ions?

• A. Covalent
• B. Metallic
• C. Ionic
• D. Hydrogen

Correct answer: C

Rationale: An ionic bond forms when one atom transfers electrons to another, resulting in the formation of positively and negatively charged ions. The attraction between these oppositely charged ions creates an electrostatic bond, known as an ionic bond. Choice A, covalent bonds, involve the sharing of electrons, not the transfer. Choice B, metallic bonds, occur between metal atoms and involve a 'sea of electrons' that are delocalized. Choice D, hydrogen bonds, are much weaker interactions between hydrogen atoms and other electronegative atoms like oxygen or nitrogen.

5. What can stop the penetration of alpha particles?

• A. Aluminum foil
• B. Glass
• C. Piece of paper
• D. Plastic

Correct answer: C

Rationale: Alpha particles can be stopped by a piece of paper due to their low penetration power. The paper acts as a shield, effectively blocking the alpha particles from passing through. In contrast, materials like aluminum foil, glass, and plastic are not as effective as a simple piece of paper in stopping alpha particles. Aluminum foil is more effective against beta particles, gamma rays, and x-rays due to its higher density. Glass and plastic also provide some protection against beta particles and gamma rays, but they are less effective than a piece of paper against alpha particles.

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