Q: Which of the following equations correctly represents the process of photosynthesis?

$$6 \text{CO}_2 + 6 \text{H}_2O + \text{sunlight} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2$$

Question 1

Which of the following best explains why sodium (Na) and chlorine (Cl) combine to form sodium chloride (NaCl) with properties very different from the original elements?

Accepted Answer

NaCl is a compound, and compounds have emergent properties different from their constituent elements.

Question 2

A patient is diagnosed with a goiter due to a deficiency of an essential trace element. Which element is most likely deficient, and what is its biological role?

Accepted Answer

Iodine (I); required for normal thyroid gland activity.

Question 3

Which process describes the use of sunflower plants to remove toxic heavy metals from contaminated soils, as seen after Hurricane Katrina?

Accepted Answer

Phytoremediation

Question 4

Given a sodium atom with atomic number 11 and mass number 23, how many neutrons does it have? Use the formula $$	ext{Number of neutrons} = 	ext{Mass number} - 	ext{Atomic number}.$$

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 5

Which statement best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 6

Radioactive isotopes are used in medical imaging, such as PET scans, because:

Accepted Answer

Their nuclei decay spontaneously, emitting particles and energy that can be traced.

Question 7

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, creating partial charges.

Question 8

What type of bond is formed when one atom donates an electron to another, resulting in oppositely charged ions that attract each other?

Accepted Answer

Ionic bond

Question 9

Which property of water allows a spider to walk on its surface, as shown in the image?

Accepted Answer

Surface tension due to cohesion among water molecules

Question 10

Why does ice float on liquid water, and why is this important for aquatic life?

Accepted Answer

Hydrogen bonds in ice are more ordered, making ice less dense than liquid water, which insulates the water below.

Question 11

A solution is made by dissolving salt in water. In this scenario, which is the solvent and which is the solute?

Accepted Answer

Water is the solvent; salt is the solute.

Question 12

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

Accepted Answer

A substance that minimizes changes in H+ or OH- concentration by accepting or donating H+ ions.

Question 13

Which of the following equations correctly represents the process of photosynthesis?

Accepted Answer

$$6 	ext{CO}_2 + 6 	ext{H}_2O + 	ext{sunlight} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2$$

Question 14

Which property of water is most responsible for the upward movement of water in plants against gravity?

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 15

Which of the following best describes van der Waals interactions?

Accepted Answer

Weak attractions due to temporary regions of positive and negative charge in molecules.

Question 16

A solution has a pH of 5. Which of the following statements is true?

Accepted Answer

The solution is acidic and has a high H+ concentration.

Question 17

Which of the following is a real-world example of hydrogen bonding?

Accepted Answer

The attraction between water molecules, allowing for surface tension.

Question 18

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

Accepted Answer

Oil is hydrophobic due to its nonpolar covalent bonds.

Question 19

Which of the following best describes the difference between a cation and an anion?

Accepted Answer

A cation has lost electrons and is positively charged; an anion has gained electrons and is negatively charged.

Chapter 2: The Chemical Context of Life – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards