Nursing Elites

1. What is the correct formula for sodium nitrate?

• A. NaNO
• B. Na NO
• C. NaNO₃
• D. Na NOâ‚‚

Correct answer: C

Rationale: The correct formula for sodium nitrate is NaNO₃. In this formula, 'Na' represents sodium, 'N' represents nitrogen, and 'O₃' represents three oxygen atoms. Sodium nitrate consists of one sodium ion (Na⁺) and one nitrate ion (NO₃⁻), which means the correct formula is NaNO₃. Choice A (NaNO) is incorrect as it lacks the subscript indicating the presence of three oxygen atoms. Choice B (Na NO) is incorrect as it includes a space between 'Na' and 'NO', which is not part of the standard chemical formula notation. Choice D (Na NO₂) is incorrect as it indicates a different compound with a nitrite ion (NO₂⁻) instead of nitrate ion.

2. Which branch of chemistry deals with the quantities and numeric relationships between compounds in a chemical reaction?

• A. Stoichiometry
• B. Molecular chemistry
• C. Atomic chemistry
• D. Thermodynamics

Correct answer: A

Rationale: Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It involves the calculation of quantities of substances consumed and produced in a chemical reaction based on the balanced chemical equation. Choice B, 'Molecular chemistry,' is incorrect as it focuses on the structure, properties, and reactions of molecules. Choice C, 'Atomic chemistry,' is incorrect as it primarily deals with the study of atoms and their interactions. Choice D, 'Thermodynamics,' is incorrect as it pertains to the study of energy and heat transfer in chemical and physical processes.

3. Which type of chemical bond is the strongest?

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

Correct answer: C

Rationale: Covalent bonds, especially those formed between non-metals, are the strongest type of chemical bond. In covalent bonds, atoms share electrons, creating a strong bond that requires a significant amount of energy to break. Choice A, ionic bonds, are strong but generally weaker than covalent bonds as they involve the transfer of electrons rather than sharing. Choice B, hydrogen bonds, are relatively weak intermolecular forces, not true chemical bonds. Choice D, metallic bonds, are strong but typically not as strong as covalent bonds. Metallic bonds involve a 'sea of electrons' shared between metal atoms, providing strength but with less directional bonding compared to covalent bonds.

4. Which element has the highest atomic number?

• A. Uranium
• B. Hydrogen
• C. Radon
• D. Bismuth

Correct answer: A

Rationale: The correct answer is Uranium. The atomic number represents the number of protons in an atom's nucleus. Among the options provided, Uranium has the highest atomic number, which is 92. Hydrogen has an atomic number of 1, Radon has an atomic number of 86, and Bismuth has an atomic number of 83. Therefore, Uranium is the element with the highest atomic number in the given choices.

5. Which element has an atomic mass greater than that of sodium?

• A. Boron
• B. Oxygen
• C. Fluorine
• D. Silicon

Correct answer: D

Rationale: Silicon has an atomic mass greater than that of sodium. The atomic mass of silicon is approximately 28.0855 u, whereas the atomic mass of sodium is approximately 22.9898 u. Therefore, silicon has a greater atomic mass compared to sodium. Boron, Oxygen, and Fluorine have atomic masses lower than sodium, making them incorrect choices in this context.

Similar Questions