Nursing Elites

1. What distinguishes one allotrope from another?

• A. Arrangement of atoms
• B. Gram atomic mass
• C. Physical state
• D. Stability

Correct answer: A

Rationale: Allotropes are different forms of the same element that exist in the same physical state but have different structures. The arrangement of atoms is what distinguishes one allotrope from another, determining their unique properties and characteristics. Gram atomic mass (Choice B) is a constant value for a specific element and does not change between different allotropes. Physical state (Choice C) refers to whether a substance is a solid, liquid, or gas, which can be the same for different allotropes of an element. Stability (Choice D) can vary between different allotropes, but it is not what always differentiates one allotrope from another. Therefore, the correct answer is the arrangement of atoms, as it is the key factor that varies across different allotropes.

2. 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.

3. How are elements arranged in the periodic table?

• A. By their atomic mass
• B. By their chemical properties
• C. By their physical state
• D. By their charge

Correct answer: B

Rationale: Elements are arranged in the periodic table based on their chemical properties, making choice B the correct answer. The periodic table is organized so that elements with similar chemical properties are grouped together in columns, known as groups or families. This arrangement allows for the identification of trends in the behavior of elements and predicting their properties based on their position in the table. Choices A, C, and D are incorrect because the periodic table primarily focuses on the chemical properties of elements, not solely on atomic mass, physical state, or charge.

4. What is the correct formula for potassium chloride?

• A. NaCl
• B. KCl
• C. KCl
• D. ClK

Correct answer: B

Rationale: The correct formula for potassium chloride is KCl. In chemical formulas, the symbol for the cation (positive ion) comes first followed by the symbol for the anion (negative ion). Potassium is represented by the symbol K, while chloride is represented by the symbol Cl. Therefore, the formula for potassium chloride is KCl. Choice A (NaCl) is the formula for sodium chloride, not potassium chloride. Choice C is a duplicate of choice B, and choice D (ClK) is an incorrect arrangement of the symbols for potassium and chloride.

5. What is a balanced equation?

• A. A description where reactants and products are not equal
• B. An equation where the number of each type of atom is the same on both sides
• C. A chemical formula showing only reactants
• D. An equation without coefficients

Correct answer: B

Rationale: A balanced equation is one where the number of each type of atom is the same on both sides, fulfilling the law of conservation of mass. This principle ensures that the total number of atoms of each element is equal in both reactants and products, signifying that no atoms are created or destroyed, but rather rearranged. Choice A is incorrect because a balanced equation has equal numbers of atoms in the reactants and products. Choice C is incorrect as a balanced equation includes both reactants and products. Choice D is incorrect because coefficients are essential in balancing equations by adjusting the number of atoms present.

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