Nursing Elites

1. Which type of chemical reaction involves two ionic compounds where the reactants yield 'switched partners'?

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

Correct answer: B

Rationale: The correct answer is 'Double replacement.' In a double replacement reaction, two ionic compounds react by exchanging ions, resulting in the formation of two new compounds where the positive and negative ions have 'switched partners.' This type of reaction is characterized by the exchange of ions between the reactants. Choice A, 'Single replacement,' involves an element replacing another in a compound, not the exchange of partners like in the given scenario. Choice C, 'Synthesis,' is the combination of two or more substances to form a more complex product, not involving the exchange of partners. Choice D, 'Decomposition,' is the breakdown of a compound into simpler substances, which is different from the scenario described in the question.

2. What is the net charge of an ionic compound?

• A. 0
• B. -1
• C. +1
• D. Variable

Correct answer: A

Rationale: The correct answer is A: 0. Ionic compounds have a net charge of 0 because they are formed by the combination of positively charged ions (cations) and negatively charged ions (anions) in a way that neutralizes their charges. This balanced combination results in an electrically neutral compound. Therefore, the net charge of an ionic compound is typically 0. Choices B, C, and D are incorrect because ionic compounds are designed to have a total neutral charge, with the positive charges balancing out the negative charges.

3. How many electrons are shared in a single covalent bond?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The correct answer is B: '2'. In a single covalent bond, two electrons are shared between two atoms. Each atom contributes one electron to form the bond, resulting in the sharing of a total of two electrons. Choice A is incorrect because a single covalent bond involves the sharing of two electrons, not one. Choices C and D are incorrect as they do not represent the correct number of electrons shared in a single covalent bond.

4. What is the name of the force that holds ionic compounds together?

• A. Covalent bonds
• B. Ionic bonds
• C. Hydrogen bonds
• D. Metallic bonds

Correct answer: B

Rationale: Ionic bonds are the forces that hold ionic compounds together. In ionic compounds, positively and negatively charged ions are held together by electrostatic forces of attraction, forming a stable structure. Covalent bonds involve the sharing of electrons between atoms, not the transfer of electrons like in ionic bonds. Hydrogen bonds are a type of intermolecular force, not the primary force in holding ionic compounds together. Metallic bonds are found in metals and involve a 'sea of electrons' that hold metal atoms together, different from the electrostatic attraction between ions in ionic compounds.

5. How many neutrons does carbon-14 have?

• A. 10
• B. 8
• C. 6
• D. 12

Correct answer: B

Rationale: The correct answer is B: 8. Carbon-14 is an isotope of carbon with 6 protons and 8 neutrons. To determine the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number. In this case, the mass number of carbon-14 is 14, and the atomic number of carbon is 6. Therefore, 14 (mass number) - 6 (atomic number) = 8 neutrons. Choices A, C, and D are incorrect because they do not reflect the correct number of neutrons in a carbon-14 atom.

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