Question 1

Which of the following statements best explains why water is an excellent solvent for ionic compounds such as NaCl?

Accepted Answer

Water molecules have partial charges that allow them to interact with and stabilize both cations and anions.

Question 2

A neutral atom of carbon-14 has an atomic number of 6 and a mass number of 14. How many neutrons does it have?

Accepted Answer

$$8$$

Question 3

Which property of water is primarily responsible for the phenomenon of surface tension?

Accepted Answer

Cohesion due to hydrogen bonding between water molecules

Question 4

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 5

Which element is most likely to form three covalent bonds based on its number of unpaired electrons in the valence shell?

Accepted Answer

Nitrogen

Question 6

What is the correct formula for the dissociation of water into ions?

Accepted Answer

$$H_2O \rightleftharpoons H^+ + OH^-$$

Question 7

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

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds hold water molecules further apart in the solid state.

Question 8

A sodium atom (Na) loses one electron to become a sodium ion (Na$$^+). $$What type of ion is Na$$^+$$ and why?

Accepted Answer

Cation, because it lost an electron

Question 9

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$$H_2O$$

Question 10

Which of the following statements about electronegativity is correct?

Accepted Answer

Electronegativity determines how strongly an atom pulls electrons in a bond.

Question 11

Which of the following best explains why water has a high specific heat?

Accepted Answer

Many hydrogen bonds must be broken for water molecules to move faster.

Question 12

If a neutral atom of nitrogen has an atomic number of 7 and a mass number of 15, how many protons, neutrons, and electrons does it have?

Accepted Answer

7 protons, 8 neutrons, 7 electrons

Question 13

Which of the following is a correct statement about the relationship between atomic number and mass number?

Accepted Answer

Mass number is the sum of protons and neutrons.

Question 14

Which of the following best describes the role of hydrogen bonds in the properties of water?

Accepted Answer

Hydrogen bonds are responsible for water's high surface tension and its ability to dissolve many substances.

Question 15

Which of the following elements is NOT one of the six most abundant elements in living organisms (CHNOPS)?

Accepted Answer

Calcium

Question 16

A molecule of methane ($$CH_4) $$has how many single covalent bonds, and what is the geometry of the molecule?

Accepted Answer

Four single covalent bonds; tetrahedral geometry

Question 17

Which of the following best explains why nonpolar molecules do not dissolve in water?

Accepted Answer

Nonpolar molecules cannot interact with the partial charges of water molecules.

Question 18

Which of the following is true about the formation of an ionic bond between sodium (Na) and chlorine (Cl)?

Accepted Answer

Chlorine gains an electron from sodium, forming Cl$$^-$$ and Na$$^+.$$

Question 19

Which of the following best describes the relationship between the number of unpaired electrons in an atom's valence shell and the number of covalent bonds it can form?

Accepted Answer

The number of unpaired electrons equals the number of covalent bonds the atom can form.

Question 20

Which of the following best explains why water is denser as a liquid than as a solid?

Accepted Answer

Hydrogen bonds in ice hold water molecules further apart than in liquid water.

Atoms, Molecules, and Properties of Water: General Biology Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards