Nursing Elites

1. What type of chemical reaction involves the combination of two elements to form a product?

• A. Decomposition
• B. Combustion
• C. Synthesis
• D. Double replacement

Correct answer: C

Rationale: A synthesis reaction involves the combination of two or more substances to form a single, more complex product. In the context of chemical reactions, it specifically refers to the combination of two elements to form a compound. Therefore, the correct answer is C. Decomposition reactions involve the breakdown of a single compound into simpler substances (opposite of synthesis). Combustion reactions involve a substance reacting with oxygen to produce heat and light, not the combination of elements. Double replacement reactions involve the exchange of ions between two compounds, leading to the formation of two new compounds, not the combination of two elements.

2. What is the correct name of ZnSO₄?

• A. Zinc sulfate
• B. Zinc sulfide
• C. Zinc sulfur
• D. Zinc oxide

Correct answer: A

Rationale: The correct name of ZnSO₄ is zinc sulfate. In this compound, zinc is combined with the polyatomic ion sulfate (SO₄). Sulfate is a common anion formed from sulfur and oxygen atoms. Therefore, the correct name for ZnSO₄ is zinc sulfate. Choice B, Zinc sulfide, is incorrect because sulfide is a different anion (S²⁻) compared to sulfate (SO₄²⁻). Choice C, Zinc sulfur, is incorrect as it does not represent the correct anion in the compound. Choice D, Zinc oxide, is incorrect as it involves an oxygen anion, not sulfate.

3. If fifty-six kilograms of a radioactive substance has a half-life of 12 days, how many days will it take the substance to decay naturally to only 7 kilograms?

• A. 8
• B. 12
• C. 36
• D. 48

Correct answer: C

Rationale: To decay from 56 kg to 7 kg, the substance needs to go through 3 half-lives (56 kg ÷ 2 ÷ 2 ÷ 2 = 7 kg). Since each half-life is 12 days, the total time required is 12 days per half-life x 3 half-lives = 36 days. Choice A is incorrect because it does not consider the concept of half-lives. Choice B is incorrect because it represents the duration of a single half-life, not the total time required for the decay. Choice D is incorrect as it does not account for the multiple half-lives needed for the substance to decay from 56 kg to 7 kg.

4. What charge do Group IIA elements typically have?

• A. 1
• B. +2
• C. -3
• D. 0

Correct answer: B

Rationale: Group IIA elements belong to the alkaline earth metals group in the periodic table. These elements typically have a charge of +2 because they readily lose two electrons to achieve a stable electron configuration. Therefore, the correct answer is B - +2. Choice A (1) is incorrect because Group IIA elements lose two electrons, not one. Choice C (-3) is incorrect because Group IIA elements do not gain electrons to have a negative charge. Choice D (0) is incorrect because Group IIA elements do lose electrons and have a positive charge, not a neutral charge.

5. What is the correct formula for calcium carbonate?

• A. CaSO₃
• B. CaCO₃
• C. Ca(OH)₂
• D. CH₃OH

Correct answer: B

Rationale: The correct formula for calcium carbonate is CaCO₃, which consists of one calcium (Ca) atom, one carbon (C) atom, and three oxygen (O) atoms. Therefore, choice B, CaCO₃, is the accurate formula for calcium carbonate. Choices A, C, and D do not represent the correct formula for calcium carbonate. Choice A, CaSO₃, is calcium sulfite, not calcium carbonate. Choice C, Ca(OH)₂, is calcium hydroxide, and choice D, CH₃OH, is methanol, none of which are correct formulas for calcium carbonate.

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