Question 1

Which of the following best explains why water is considered a versatile solvent in biological systems?

Accepted Answer

Water's ability to form hydrogen bonds with both polar and ionic compounds enables it to dissolve a wide variety of substances.

Question 2

A sodium atom ($$Na) $$loses one electron to become a sodium ion ($$Na^+). $$What type of bond is formed when $$Na^+$$ interacts with a chloride ion ($$Cl^-) in $$table salt?

Accepted Answer

Ionic bond

Question 3

Which property of water is most directly responsible for the phenomenon where a paperclip can float on its surface?

Accepted Answer

Cohesive properties due to hydrogen bonding

Question 4

Given the electronegativity scale $$O \u003e N \u003e C = H$$, which molecule would have the most polar covalent bonds?

Accepted Answer

Water ($$H_2O)$$

Question 5

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds form between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 6

Which of the following best describes the difference between an element and a compound?

Accepted Answer

An element consists entirely of one type of atom, while a compound is made of two or more different elements chemically bonded.

Question 7

A molecule of water ($$H_2O) $$has a bent shape. Which factor is primarily responsible for this molecular geometry?

Accepted Answer

The presence of two lone pairs of electrons on the oxygen atom

Question 8

Which of the following functional groups is most likely to form hydrogen bonds with water, increasing a molecule's solubility?

Accepted Answer

Hydroxyl group ($$-OH)$$

Question 9

If an atom has an atomic number of 8 and a mass number of 16, how many neutrons does it have?

Accepted Answer

8

Question 10

Which property of water allows lakes to moderate temperature changes during seasonal transitions?

Accepted Answer

Ability to stabilize temperature due to high specific heat

Question 11

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges on the atoms.

Question 12

Which of the following is NOT one of the four most common atoms found in living cells?

Accepted Answer

Phosphorus

Question 13

What is the atomic number of an atom with 6 protons, 6 neutrons, and 6 electrons?

Accepted Answer

6

Question 14

Which of the following scenarios best illustrates the concept of van der Waals forces?

Accepted Answer

Temporary attractions between nonpolar molecules due to fluctuating electron distributions

Question 15

Why does ice float on water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds hold water molecules in a rigid, open structure.

Question 16

Which of the following best explains why water has a high surface tension?

Accepted Answer

Hydrogen bonds between water molecules create a cohesive network at the surface.

Question 17

A molecule contains a carbon atom bonded to four different atoms. Which property of carbon allows for this diversity in organic molecules?

Accepted Answer

Carbon can form up to four covalent bonds due to its four valence electrons.

Question 18

Which of the following best describes the role of water in the assembly and disassembly of biological polymers?

Accepted Answer

Water participates in both dehydration synthesis (removal of water to form bonds) and hydrolysis (addition of water to break bonds).

Question 19

Which of the following best explains why oxygen is more electronegative than hydrogen?

Accepted Answer

Oxygen has more protons in its nucleus, attracting electrons more strongly.

Water and Carbon: The Chemical Basis of Life – Study Notes

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