Question 1

Which subatomic particle determines the chemical reactivity of an element?

Accepted Answer

Electron

Question 2

What is the main reason water molecules are polar?

Accepted Answer

The oxygen atom is more electronegative, causing unequal sharing of electrons

Question 3

Which type of chemical bond involves the sharing of electrons between two atoms?

Accepted Answer

Covalent bond

Question 4

If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 6, Mass number: 12

Question 5

Which property of water allows plants to transport water from roots to leaves against gravity?

Accepted Answer

Transpiration

Question 6

What is the maximum number of hydrogen bonds a single water molecule can form at one time?

Accepted Answer

$$4$$

Question 7

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the attraction between oppositely charged ions

Question 8

Why does sodium chloride (NaCl) dissolve easily in water?

Accepted Answer

Water's polarity allows it to surround and separate Na$$^+$$ and Cl$$^-$$ ions

Question 9

Which of the following is a consequence of water's high specific heat for living organisms?

Accepted Answer

Water stabilizes temperatures in organisms and environments

Question 10

A molecule of methane (CH$$_4) $$has which type of covalent bonds?

Accepted Answer

Nonpolar covalent bonds

Question 11

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

Accepted Answer

Hydrogen bonds in ice create a lattice that is less dense than liquid water

Question 12

Which of the following is NOT a property of water that contributes to Earth's fitness for life?

Accepted Answer

Nonpolar nature

Question 13

Which statement about hydrogen bonds is correct?

Accepted Answer

They are relatively weak bonds formed between a hydrogen atom and a strongly electronegative atom of another molecule

Question 14

If a carbon atom has 6 protons and 8 neutrons, what is its isotope called?

Accepted Answer

Carbon-14

Question 15

Which of the following interactions is responsible for the three-dimensional shape of large biological molecules?

Accepted Answer

Van der Waals interactions

Question 16

Which property of water is most directly responsible for the formation of droplets on a windshield?

Accepted Answer

Adhesion

Question 17

Which of the following best describes electronegativity?

Accepted Answer

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

Question 18

A solution has a high concentration of H$$^+$$ ions. What can you infer about its pH?

Accepted Answer

It is acidic

Question 19

Which of the following is a direct result of water's cohesion?

Accepted Answer

Water molecules stick to each other, allowing surface tension

Question 20

Which of the following best explains why oxygen and nitrogen atoms tend to attract electrons more strongly in a covalent bond?

Accepted Answer

They have higher electronegativity

The Chemical Context of Life & Water: Foundations for Biology

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