Nursing Elites

1. What is the simplest form of a substance that is represented by a letter or letters?

• A. Compound
• B. Mixture
• C. Element
• D. Molecule

Correct answer: C

Rationale: The correct answer is C, 'Element.' An element is the most basic form of a substance that cannot be broken down further by chemical reactions. Each element is represented by a unique symbol, typically consisting of one or two letters. Choice A, 'Compound,' is incorrect as compounds are formed by the combination of two or more elements. Choice B, 'Mixture,' is also incorrect as mixtures are composed of two or more substances physically combined. Choice D, 'Molecule,' refers to the smallest unit of a compound that retains the chemical properties of that compound, not the simplest form of a substance represented by a symbol.

2. 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.

3. What are the horizontal rows of the periodic table called?

• A. Periods
• B. Families
• C. Groups
• D. Columns

Correct answer: A

Rationale: The correct answer is A: Periods. Rows in the periodic table are called periods. They are arranged horizontally from left to right and represent the energy levels of the elements. Each period starts a new energy level or shell, indicating the number of electron shells an element has. Choices B, C, and D are incorrect. Families and groups refer to vertical columns in the periodic table that share similar chemical properties, while columns are vertical arrangements of elements known as groups or families.

4. What charge do Group VA elements typically have?

• A. -1
• B. -2
• C. -3
• D. 0

Correct answer: C

Rationale: Group VA elements, also known as Group 15 elements, typically have a charge of -3. This is because they have five valence electrons and tend to gain three electrons to achieve a stable octet configuration, resulting in a -3 charge. Choice A (-1) and Choice B (-2) are incorrect because Group VA elements need to gain three electrons to reach a stable electron configuration, not just one or two. Choice D (0) is also incorrect because Group VA elements do not lose electrons to form a charge of 0.

5. What determines polarity in a molecule?

• A. Bond length
• B. Bond strength
• C. Electronegativity
• D. Molecular weight

Correct answer: C

Rationale: Polarity in a molecule is determined by the difference in electronegativity between the atoms forming the bond. The greater the difference in electronegativity, the more polar the bond and molecule become. This difference leads to an uneven distribution of electron density within the bond, creating partial positive and negative charges on the atoms involved. Choices A, B, and D are incorrect. Bond length and strength do not determine polarity, and molecular weight is not directly related to the polarity of a molecule.

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