Nursing Elites

1. Which of the following represents a hydride ion?

• A. H⁻
• B. H⁺
• C. OH⁻
• D. HCl

Correct answer: A

Rationale: The hydride ion is denoted by H⁻, indicating that it has gained an extra electron to complete its valence shell, resulting in a full octet and a net charge of -1. This ion is commonly found in metal hydrides and plays a significant role in various chemical reactions. Option B, H⁺, represents a proton with a positive charge. Option C, OH⁻, represents the hydroxide ion, consisting of oxygen and hydrogen. Option D, HCl, is a compound composed of hydrogen and chlorine ions, not a hydride ion.

2. When balanced, the reaction Fe + O₂ → FeO will be?

• A. 2Fe + 2Oâ‚‚ → 3FeO
• B. 4Fe + 6Oâ‚‚ → 6FeO
• C. 2Fe + 3Oâ‚‚ → 2FeO
• D. 4Fe + 3Oâ‚‚ → 2FeO

Correct answer: C

Rationale: To balance the chemical equation Fe + O₂ → FeO, the coefficients needed are 2 for Fe and 1 for O. Therefore, the balanced equation becomes 2Fe + O₂ → 2FeO, which translates into 2Fe + 3O₂ → 2FeO. This corresponds to option C. Choice A has the incorrect number of oxygen molecules. Choice B has an incorrect number of Fe atoms on the product side. Choice D also has an incorrect number of Fe atoms on the product side.

3. 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.

4. What defines a balanced chemical equation?

• A. An equation where the number of atoms of each element is the same on both sides
• B. An equation where there are more products than reactants
• C. An equation where the number of molecules is balanced
• D. An equation with equal masses on both sides

Correct answer: A

Rationale: A balanced chemical equation is one in which the number of atoms of each element is the same on both sides. This balance ensures the law of conservation of mass is upheld, where the total mass of the reactants equals the total mass of the products. Options B, C, and D are incorrect. Option B is incorrect as a balanced equation has an equal number of products and reactants. Option C is incorrect as balancing refers to the number of atoms, not molecules. Option D is incorrect as balancing is based on the number of atoms, not masses. Therefore, option A is the correct choice as it accurately describes a balanced chemical equation.

5. What is the chemical symbol for sodium?

• A. N
• B. Na
• C. Cl
• D. H

Correct answer: B

Rationale: The correct chemical symbol for sodium is 'Na.' In the periodic table, sodium is represented by the symbol 'Na,' derived from its Latin name 'natrium.' The symbol 'N' represents nitrogen, not sodium. 'Cl' is the symbol for chlorine, and 'H' is the symbol for hydrogen. Therefore, 'Na' is the correct chemical symbol for sodium.

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