Nursing Elites

1. What is the oxidation state of the nitrogen atom in the compound NH3?

• A. -3
• B. -1
• C. +1
• D. +3

Correct answer: B

Rationale: In the compound NH3, nitrogen is bonded to three hydrogen atoms. Hydrogen is always assigned an oxidation state of +1. Since the overall charge of NH3 is zero, the oxidation state of nitrogen must be -1 to balance out the hydrogen's +1 oxidation state. Therefore, the correct oxidation state of the nitrogen atom in NH3 is -1. Choice A (-3) is incorrect because it does not account for the electronegativity of hydrogen. Choice C (+1) and Choice D (+3) are incorrect as the nitrogen atom in NH3 needs to balance the +1 oxidation state of each hydrogen atom, resulting in a total of -3 to maintain the compound's charge neutrality.

2. What is the name of the compound CH₃-CH₂-CH₂-CH₃?

• A. Cyclobutane
• B. Butane
• C. Butene
• D. Butyne

Correct answer: B

Rationale: The compound CH₃-CH₂-CH₂-CH₃ is named butane. Butane is a straight-chain alkane comprising four carbon atoms connected by single bonds. The prefix 'but-' denotes the presence of four carbon atoms, while the suffix '-ane' indicates it is an alkane with single bonds between the carbon atoms. Choice A, Cyclobutane, is incorrect as it refers to a cyclic hydrocarbon with four carbon atoms in a ring structure. Choice C, Butene, is incorrect because it is an alkene with a double bond between two carbon atoms, not a saturated hydrocarbon like butane. Choice D, Butyne, is also incorrect as it is an alkyne with a triple bond between two carbon atoms, unlike the single bonds in butane.

3. Which of the following elements is the most electronegative?

• A. Oxygen
• B. Fluorine
• C. Nitrogen
• D. Sodium

Correct answer: B

Rationale: Fluorine is the most electronegative element on the periodic table. It has the highest electronegativity value, indicating its strong ability to attract electrons in a chemical bond. This property makes it highly reactive, explaining why it is the correct answer in this question. Oxygen and Nitrogen are also electronegative elements, but they are not as electronegative as Fluorine. Sodium, on the other hand, is not electronegative; it is an electropositive element.

4. Arsenic and silicon are examples of ___________.

• A. metals
• B. nonmetals
• C. metalloids
• D. heavy metals

Correct answer: C

Rationale: Arsenic and silicon are both examples of metalloids. Metalloids have properties that lie between those of metals and nonmetals. They exhibit characteristics of both groups, making them versatile elements with various applications in different industries. Choice A (metals) is incorrect as arsenic and silicon do not exhibit typical metallic properties. Choice B (nonmetals) is incorrect as they do not possess all the properties of nonmetals. Choice D (heavy metals) is incorrect as heavy metals refer to a different group of elements with high atomic weights, and arsenic and silicon are not categorized as heavy metals.

5. What are positively charged ions called?

• A. Neutrons
• B. Protons
• C. Cations
• D. Electrons

Correct answer: C

Rationale: Positively charged ions are called cations. When an atom loses electrons, it becomes positively charged and is referred to as a cation. Neutrons are neutral particles found in the nucleus of an atom, not charged. Protons are positively charged particles in the nucleus. Electrons are negatively charged particles orbiting the nucleus, not positively charged ions.

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