Nursing Elites

1. Among the following elements, which is a nonmetal?

• A. Mercury
• B. Magnesium
• C. Sulfur
• D. Potassium

Correct answer: C

Rationale: Sulfur is a nonmetal as it is located on the right side of the periodic table. Nonmetals generally exhibit properties such as being brittle, poor conductors of heat and electricity, and having lower melting points compared to metals. Mercury (A), Magnesium (B), and Potassium (D) are all metals due to their metallic properties. Mercury is a liquid metal at room temperature, Magnesium is a solid metal, and Potassium is a solid metal as well. Therefore, the correct answer is C, Sulfur.

2. What term is used to describe the emission of particles from an unstable nucleus?

• A. Radioactivity
• B. Radiation
• C. Decay
• D. Fusion

Correct answer: A

Rationale: Radioactivity is the term used to describe the emission of particles from an unstable nucleus. When a nucleus is unstable, it undergoes radioactive decay by emitting particles such as alpha or beta particles. This process releases energy and transforms the unstable nucleus into a more stable configuration. Choice B, 'Radiation,' is a broad term that encompasses various forms of energy emitted from a source; it is not specific to the emission from an unstable nucleus. Choice C, 'Decay,' is closely related but doesn't specifically indicate the emission of particles from an unstable nucleus. Choice D, 'Fusion,' refers to the process of combining nuclei to form a heavier nucleus, not the emission of particles from an unstable nucleus.

3. To the nearest whole number, what is the mass of one mole of sodium chloride?

• A. 36 g/mol
• B. 43 g/mol
• C. 58 g/mol
• D. 72 g/mol

Correct answer: C

Rationale: The molar mass of sodium chloride (NaCl) is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of sodium is approximately 23 g/mol and chlorine is approximately 35.5 g/mol. Adding these two atomic masses gives us a molar mass of approximately 58 g/mol for sodium chloride (NaCl). Therefore, the correct answer is C, 58 g/mol. Choice A (36 g/mol) is incorrect as it does not account for the individual atomic masses of sodium and chlorine. Choice B (43 g/mol) and choice D (72 g/mol) are also incorrect as they do not reflect the accurate molar mass of sodium chloride.

4. How many electrons are shared in a single covalent bond?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The correct answer is B: '2'. In a single covalent bond, two electrons are shared between two atoms. Each atom contributes one electron to form the bond, resulting in the sharing of a total of two electrons. Choice A is incorrect because a single covalent bond involves the sharing of two electrons, not one. Choices C and D are incorrect as they do not represent the correct number of electrons shared in a single covalent bond.

5. What type of bond is present in sodium chloride?

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

Correct answer: B

Rationale: Ionic bonds are found in sodium chloride. In an ionic bond, one atom donates an electron to another atom, resulting in the formation of positively and negatively charged ions that are held together by electrostatic forces of attraction. Sodium chloride is a classic example of an ionic compound, where sodium (Na) donates an electron to chlorine (Cl), forming Na+ and Cl- ions that are attracted to each other, creating a crystal lattice structure. Covalent bonds involve the sharing of electron pairs between atoms, which is not the case in sodium chloride. Metallic bonds occur in metals where electrons are delocalized and shared across a lattice, unlike the specific transfer seen in ionic bonds. Hydrogen bonds are a type of intermolecular force, not the primary bond type present in sodium chloride.

Similar Questions