Nursing Elites

1. Which is a property of an ionic compound?

• A. Low melting point
• B. Poor conductivity
• C. Shared electrons
• D. Crystalline shape

Correct answer: D

Rationale: Ionic compounds are composed of positively and negatively charged ions that are held together by strong electrostatic forces. These ions arrange themselves in a repeating pattern to form a stable and orderly structure known as a crystalline shape. This is a characteristic property of ionic compounds, making choice D the correct answer. Choices A, B, and C are incorrect because ionic compounds typically have high melting points, good conductivity in the molten or dissolved state, and do not involve shared electrons but rather the transfer of electrons between atoms.

2. What does the mass number minus the atomic number equal?

• A. Number of electrons
• B. Number of neutrons
• C. Number of protons
• D. Number of isotopes

Correct answer: B

Rationale: The mass number of an atom represents the total number of protons and neutrons in its nucleus. The atomic number indicates the number of protons in the nucleus. The difference between the mass number and the atomic number provides the number of neutrons present in the nucleus of an atom. Therefore, mass number minus atomic number equals the number of neutrons. Choice A is incorrect because the number of electrons is not determined by the mass number and atomic number. Choice C is incorrect as it represents the number of protons, not the difference between the mass number and atomic number. Choice D is incorrect as isotopes refer to atoms of the same element with different numbers of neutrons, not the difference between mass number and atomic number.

3. What are the columns of the periodic table called?

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

Correct answer: C

Rationale: In the periodic table, columns are referred to as groups, not periods, families, or rows. These groups share similar chemical properties due to the arrangement of elements within each group, which is based on the number of valence electrons. The vertical columns help classify elements with similar characteristics. Periods refer to the rows of the periodic table, while families or groups are the vertical columns.

4. On the periodic table, families of elements with similar properties appear in the same _________.

• A. row
• B. principal energy level
• C. period
• D. column

Correct answer: D

Rationale: Families of elements with similar properties appear in the same column on the periodic table. Columns are also known as groups, and elements within the same group have similar chemical and physical properties due to their identical number of valence electrons. Therefore, the correct answer is 'column.' Choice A, 'row,' is incorrect because rows on the periodic table are called periods, not families or groups of elements. Choice B, 'principal energy level,' is incorrect as it refers to the energy levels of electrons around the nucleus of an atom, not the arrangement of elements with similar properties on the periodic table. Choice C, 'period,' is incorrect as periods represent horizontal rows on the periodic table, where elements do not necessarily have similar properties compared to elements in the same column.

5. The molar mass of glucose is 180 g/mol. If an IV solution contains 5 g of glucose in 100 g of water, what is the molarity of the solution?

• A. 0.28M
• B. 1.8M
• C. 2.8M
• D. 18M

Correct answer: C

Rationale: To calculate the molarity of the solution, we first need to determine the moles of solute (glucose) and solvent (water) separately. The molar mass of glucose is 180 g/mol. First, calculate the moles of glucose: 5 g / 180 g/mol = 0.02778 mol of glucose. Next, calculate the moles of water: 100 g / 18 g/mol = 5.56 mol of water. Now, calculate the total moles in the solution: 0.02778 mol glucose + 5.56 mol water = 5.5878 mol. Finally, calculate the molarity: Molarity = moles of solute / liters of solution. Since the total mass of the solution is 100 g + 5 g = 105 g = 0.105 kg, which is equal to 0.105 L, the molarity is 5.5878 mol / 0.105 L = 53.22 M, which rounds to 2.8M. Therefore, the correct answer is 2.8M. Choices A, B, and D are incorrect because they do not reflect the accurate molarity calculation based on the moles of solute and volume of the solution.

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