Question 1

Which of the following best explains why water has a high specific heat compared to many other substances?

Accepted Answer

Hydrogen bonds between water molecules require additional energy to disrupt, increasing the specific heat.

Question 2

A radioactive isotope of carbon, $$^{14}C$$, is used in dating ancient artifacts. What makes $$^{14}C$$ different from the most common carbon isotope, $$^{12}C$$?

Accepted Answer

$$^{14}C$$ has more neutrons than $$^{12}C.$$

Question 3

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the complete transfer of electrons from one atom to another, resulting in oppositely charged ions.

Question 4

A molecule of water (H$$_2O) is $$described as polar. What property of the water molecule causes this polarity?

Accepted Answer

The oxygen atom has a higher electronegativity, pulling shared electrons closer and creating partial charges.

Question 5

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules are nonpolar and cannot form favorable interactions with polar water molecules.

Question 6

A solution is made by dissolving 1 mole of NaCl in enough water to make 1 liter of solution. What is the molarity of NaCl in this solution?

Accepted Answer

1 M

Question 7

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids donate protons ($$H^+) $$and bases accept protons ($$H^+) in $$solution.

Question 8

Which of the following best describes a buffer in a biological system?

Accepted Answer

A compound that maintains a constant pH by accepting or donating protons ($$H^+) as $$needed.

Question 9

Which of the following is a correct representation of a dehydration (condensation) reaction?

Accepted Answer

$$\mathrm{Monomer}_1 + \mathrm{Monomer}_2 \rightarrow \mathrm{Polymer} + H_2O$$

Question 10

A scientist is studying a molecule with the formula $$C_6H_{12}O_6$. Which of the following best describes this molecule?

Accepted Answer

It is a molecule composed of different elements bonded together.

Question 11

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create an open lattice structure, making it less dense than liquid water.

Question 12

Which of the following is the best definition of electronegativity?

Accepted Answer

The ability of an atom to attract shared electrons in a covalent bond.

Question 13

A molecule has a region with a partial positive charge and a region with a partial negative charge. What type of molecule is this?

Accepted Answer

Polar molecule

Question 14

Which of the following best describes the process of hydrolysis?

Accepted Answer

A water molecule is added to break a polymer into monomers.

Question 15

Which of the following is true about the atomic number of an element?

Accepted Answer

It is equal to the number of protons in the atom.

Question 16

A solution has a pH of 4. How does its hydrogen ion concentration compare to a solution with a pH of 7?

Accepted Answer

It is 1000 times higher.

Question 17

Which of the following functional groups acts as an acid by releasing a proton ($$H^+) in $$solution?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 18

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of one or more pairs of electrons between atoms.

Question 19

Which of the following is a property of water that is critical for life and is a result of hydrogen bonding?

Accepted Answer

High surface tension

Question 20

A biologist adds a drop of water to a glass slide and observes that the water forms a bead rather than spreading out. Which property of water is responsible for this observation?

Accepted Answer

Cohesion

Atoms, Ions, Molecules, and Water: Foundations of General Biology

Guida di studio - Domande di pratica

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