Nursing Elites

1. Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.

• A. Ionic bonds involve electron sharing, while metallic bonds involve electron transfer.
• B. Ionic bonds are weak and directional, while metallic bonds are strong and non-directional.
• C. Ionic bonds exist between metals and non-metals, while metallic bonds exist only between metals.
• D. Ionic bonds form discrete molecules, while metallic bonds form extended structures.

Correct answer: C

Rationale: Ionic bonds typically form between metals and non-metals, where one atom donates electrons (cation) and the other accepts electrons (anion). This results in the transfer of electrons. Metallic bonds, on the other hand, occur between metal atoms where electrons are shared among a sea of delocalized electrons, leading to the characteristic properties of metals like malleability and conductivity. Choice A is incorrect because ionic bonds involve electron transfer, not sharing. Choice B is incorrect as ionic bonds are strong, not weak, and are non-directional, while metallic bonds are strong and non-directional. Choice D is incorrect as ionic bonds do not form discrete molecules but rather a lattice structure, whereas metallic bonds form extended structures.

2. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: A

Rationale: The correct formula for calculating molarity is M = n/V. In this formula, 'M' represents molarity, 'n' represents the number of moles of solute, and 'V' represents the volume of the solution in liters. Molarity is defined as the number of moles of solute per liter of solution, hence the ratio of moles to volume. Choice B, 'M = n/L', is incorrect because 'L' should represent liters instead of the number of moles. Choice C, 'M = mol/L', is incorrect as it does not include the representation of the number of moles 'n'. Choice D, 'M = mol/dm³', is incorrect because 'dm³' is a volume unit equal to a liter, but the correct representation should be in terms of the volume of the solution in liters. Therefore, the correct answer is M = n/V.

3. How many kilograms are in 1,800 grams?

• A. 0.18
• B. 1.8
• C. 18
• D. 180

Correct answer: B

Rationale: To convert grams to kilograms, divide by 1,000 since there are 1,000 grams in a kilogram. Therefore, 1,800 grams is equal to 1.8 kilograms (1,800 / 1,000 = 1.8). Choice A (0.18) is incorrect because it incorrectly shifted the decimal point. Choice C (18) is incorrect as it represents the direct conversion without dividing by 1,000. Choice D (180) is incorrect as it is in the hundreds and not the correct conversion to kilograms. The correct answer is B.

4. What is the science of classifying organisms into different groups based on their evolutionary relationships called?

• A. Taxonomy
• B. Microbiology
• C. Genetics
• D. Epidemiology

Correct answer: A

Rationale: Taxonomy is the science of classifying organisms into different groups based on their evolutionary relationships. It involves identifying, naming, and categorizing living organisms according to their similarities and differences, helping us understand the diversity of life. Microbiology (option B) focuses on the study of microorganisms. Genetics (option C) deals with genes and heredity. Epidemiology (option D) explores the distribution and determinants of health-related states or events in populations. Therefore, the correct answer is Taxonomy as it specifically pertains to the classification of organisms based on their evolutionary relationships.

5. Which of the following is an example of an unsaturated fatty acid?

• A. Stearic acid
• B. Palmitic acid
• C. Oleic acid
• D. Butyric acid

Correct answer: C

Rationale: Oleic acid is an example of an unsaturated fatty acid because it contains one or more double bonds in its hydrocarbon chain, leading to kinks in the chain structure. This unsaturation gives it a lower melting point compared to saturated fatty acids. Stearic acid (A), Palmitic acid (B), and Butyric acid (D) are examples of saturated fatty acids as they do not contain any double bonds in their hydrocarbon chains, leading to a straight structure and higher melting points.

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