Nursing Elites

1. Which of these types of intermolecular force is weakest?

• A. Dipole-dipole interaction
• B. London dispersion force
• C. Hydrogen bonding
• D. Ionic bonding

Correct answer: B

Rationale: The correct answer is B, London dispersion force. London dispersion forces are the weakest type of intermolecular force among the options provided. These forces arise from temporary fluctuations in electron distribution within molecules, leading to temporary dipoles. London dispersion forces are present in all molecules and are generally weaker than dipole-dipole interactions, hydrogen bonding, and ionic bonding. Dipole-dipole interactions are stronger than London dispersion forces as they involve permanent dipoles in molecules. Hydrogen bonding is stronger than both London dispersion and dipole-dipole interactions as it is a special type of dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like oxygen or nitrogen. Ionic bonding is the strongest type of intermolecular force among the options, but it is not the correct answer for the weakest type of force.

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 of these elements has the greatest atomic mass?

• A. Au
• B. Ba
• C. I
• D. W

Correct answer: D

Rationale: Among the elements listed, Tungsten (W) has the greatest atomic mass. The atomic mass of Tungsten is approximately 183.84 atomic mass units (amu), while the atomic masses of the other elements listed are as follows: Gold (Au) is around 196.97 amu, Barium (Ba) is approximately 137.33 amu, and Iodine (I) is about 126.90 amu. Therefore, Tungsten (W) has the greatest atomic mass out of the given elements. Gold (Au) has a higher atomic mass than Barium (Ba) and Iodine (I), making choices A, B, and C incorrect.

4. What is the mass number of an atom with 6 protons, 6 neutrons, and 6 electrons?

• A. 12
• B. 18
• C. 6
• D. 8

Correct answer: A

Rationale: The mass number of an atom is the sum of protons and neutrons. In this case, the atom has 6 protons and 6 neutrons, thus the mass number is 6 + 6 = 12. Therefore, choice A (12) is the correct answer. Choices B (18), C (6), and D (8) are incorrect because the mass number is determined by the sum of protons and neutrons, not the number of electrons or a different combination of particles.

5. If electrons are not shared equally in a covalent bond, the bond is what?

• A. Polar
• B. Non-polar
• C. Ionic
• D. Hydrogen

Correct answer: A

Rationale: A polar covalent bond occurs when electrons are shared unequally between atoms. In this type of bond, one atom has a stronger pull on the shared electrons, leading to a partial positive and partial negative charge distribution within the molecule. Choice B, non-polar, is incorrect because in non-polar covalent bonds, electrons are shared equally between atoms. Choice C, ionic, is incorrect as ionic bonds involve a transfer of electrons rather than sharing. Choice D, hydrogen, is incorrect as it does not describe the nature of a covalent bond.

Similar Questions