Question 1

Which of the following elements is most abundant in living cells and is essential for forming covalent bonds in organic molecules?

Accepted Answer

Oxygen (O)

Question 2

A carbon atom has 4 electrons in its outermost shell. How many covalent bonds can it form to achieve stability?

Accepted Answer

$$4$$

Question 3

Which property determines whether a covalent bond between two atoms is polar or nonpolar?

Accepted Answer

Electronegativity difference

Question 4

When sodium ($$Na) $$reacts with chlorine ($$Cl) to $$form table salt ($$NaCl$$), what type of bond is formed and why?

Accepted Answer

Ionic bond, because electrons are transferred from $$Na to$$ $$Cl$$

Question 5

Which of the following molecules is overall nonpolar and hydrophobic, despite containing polar covalent bonds?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 6

What is the maximum number of electrons that can occupy the second electron shell of an atom?

Accepted Answer

$$8$$

Question 7

Which type of bond is responsible for the cohesion between water molecules, allowing for surface tension?

Accepted Answer

Hydrogen bond

Question 8

A molecule contains mostly nonpolar covalent bonds. How will it likely interact with water?

Accepted Answer

It will be hydrophobic and not dissolve well

Question 9

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a partially positive hydrogen atom and a partially negative atom

Question 10

Which of the following is NOT a major class of biological macromolecules?

Accepted Answer

Minerals

Question 11

If a molecule is hydrophilic, what can you infer about its chemical structure?

Accepted Answer

It contains polar covalent bonds and can form hydrogen bonds with water

Question 12

Which of the following statements about covalent bonds is TRUE?

Accepted Answer

Covalent bonds are stronger than hydrogen bonds

Question 13

Which element is LEAST likely to form more than two covalent bonds in biological molecules?

Accepted Answer

Oxygen (O)

Question 14

A molecule has the following structure: $$C-H. $$What type of covalent bond is this?

Accepted Answer

Nonpolar covalent bond

Question 15

Which of the following is a monomer that forms nucleic acids?

Accepted Answer

Nucleotide

Question 16

Which scenario best illustrates the formation of an ionic bond?

Accepted Answer

A sodium atom donates an electron to a chlorine atom, resulting in $$Na^+$$ and $$Cl^-$$ ions

Question 17

Which of the following best explains why water is a liquid at room temperature?

Accepted Answer

Hydrogen bonds between water molecules create cohesion

Question 18

Which of the following statements about electron shells is correct?

Accepted Answer

Atoms are most stable when their outermost shell is full

Question 19

Which of the following is a correct statement about the behavior of hydrophobic molecules in water?

Accepted Answer

They aggregate together, minimizing contact with water

Question 20

Which of the following is the correct order of electronegativity for the elements of life, from highest to lowest?

Accepted Answer

$$O \u003e N \u003e C \u003e H$$

The Chemistry of Life: Atoms, Bonds, and Biological Macromolecules

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