Question 1

Which statement best explains why researchers used bonding theories to design drugs that inhibit HIV-protease?

Accepted Answer

Bonding theories predict how atoms bond together, allowing simulation of drug interactions with HIV-protease.

Question 2

According to the Lewis model, what is the primary difference between an ionic bond and a covalent bond?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 3

Which element is an exception to the octet rule and achieves stability with only two electrons in its valence shell?

Accepted Answer

Helium

Question 4

What is the correct Lewis structure for the ionic compound MgO?

Accepted Answer

$$ \mathrm{Mg}^{2+} \; [\cdot\cdot\cdot\cdot\cdot\cdot\cdot\cdot \mathrm{O}]^{2-} $$

Question 5

When writing Lewis structures for covalent compounds, what is the first step according to the guidelines?

Accepted Answer

Write the correct skeletal structure for the molecule.

Question 6

Which molecule is an example of a diatomic molecule formed by a triple bond?

Accepted Answer

$$ \mathrm{N}_2 $$

Question 7

What is the molecular geometry of $$ \mathrm{NH}_3  ($$ammonia) according to VSEPR theory?

Accepted Answer

Trigonal pyramidal

Question 8

Which of the following best describes the polarity of the $$ \mathrm{CO}_2 $$ molecule?

Accepted Answer

Nonpolar molecule because the dipole moments cancel due to linear geometry.

Question 9

A molecule has three identical polar bonds arranged at 120° from each other. What is the overall polarity of the molecule?

Accepted Answer

The molecule is nonpolar because the dipole moments cancel.

Question 10

Which statement correctly describes the effect of electronegativity difference on bond type?

Accepted Answer

An intermediate electronegativity difference results in a polar covalent bond.

Question 11

Why do water and oil not mix, based on molecular polarity?

Accepted Answer

Water molecules are polar and oil molecules are nonpolar, causing them to repel each other.

Question 12

Which of the following is a correct statement about resonance structures?

Accepted Answer

Resonance structures are equally correct Lewis structures for the same molecule, and the true structure is an average of them.

Question 13

Which of the following molecules is an example of a free radical implicated in aging theories?

Accepted Answer

$$ \mathrm{OH} $$

Question 14

What is the correct chemical formula for the ionic compound formed between sodium and sulfur?

Accepted Answer

$$ \mathrm{Na}_2\mathrm{S} $$

Question 15

Which step is necessary when writing the Lewis structure for a polyatomic ion?

Accepted Answer

Add one electron for each negative charge and subtract one for each positive charge.

Question 16

Which of the following statements about artificial sweeteners is correct?

Accepted Answer

Artificial sweeteners taste sweet because their molecular shape allows them to fit into the active site of taste receptor proteins.

Question 17

Which of the following best describes a bonding pair electron in a Lewis structure?

Accepted Answer

A pair of electrons shared between two atoms.

Question 18

Which molecule has a bent molecular geometry due to the presence of two lone pairs on the central atom?

Accepted Answer

$$ \mathrm{H}_2O $$

Question 19

Which element has the highest electronegativity according to the Pauling scale?

Accepted Answer

Fluorine

Chapter 10: Chemical Bonding – Lewis Model, Ionic and Covalent Bonds, and Molecular Structure

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