Question 1

Which of the following best describes the process of phytoremediation as used with sunflowers after environmental disasters?

Accepted Answer

Sunflowers absorb heavy metals from polluted soils, reducing toxicity and allowing for land redevelopment.

Question 2

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 3

A neutral atom of sodium has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 4

Which statement about isotopes is correct?

Accepted Answer

Isotopes of an element have different numbers of neutrons.

Question 5

Which of the following is a real-world application of radioactive isotopes?

Accepted Answer

Dating fossils using carbon-14

Question 6

What is the main reason water is able to dissolve so many substances?

Accepted Answer

Water is a polar molecule, allowing it to interact with ionic and polar substances.

Question 7

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

Accepted Answer

Hydrogen bonds in ice are more ordered, making ice less dense than liquid water.

Question 8

A solution has a pH of 4. Which of the following statements is true?

Accepted Answer

The solution is acidic and has a high concentration of H$$^+$$ ions.

Question 9

Which of the following best describes the difference between covalent and ionic bonds?

Accepted Answer

Covalent bonds involve sharing electrons, while ionic bonds involve the transfer of electrons.

Question 10

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

Accepted Answer

High surface tension due to hydrogen bonding

Question 11

Which of the following best explains why geckos can walk on walls?

Accepted Answer

Van der Waals interactions between the gecko’s foot hairs and the wall surface provide enough collective strength.

Question 12

Which of the following is an example of a buffer in biological systems?

Accepted Answer

A substance that minimizes changes in H$$^+$$ and OH$$^-$$ concentrations

Question 13

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds form between a hydrogen atom and an electronegative atom, such as oxygen or nitrogen.

Question 14

A molecule of water (H$$_2O) is $$held together by which type of bond?

Accepted Answer

Polar covalent bond

Question 15

Which of the following best describes the role of adhesion in water transport in plants?

Accepted Answer

Adhesion allows water molecules to stick to the walls of plant vessels, helping counteract gravity.

Question 16

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

Accepted Answer

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

Question 17

Which of the following best describes a hydrophobic substance?

Accepted Answer

A substance that does not have an affinity for water, usually due to nonpolar bonds

Question 18

Which of the following is true about trace elements?

Accepted Answer

They are only required in minute quantities but are essential for normal biological functions.

Question 19

Which of the following best explains why atoms with incomplete valence shells are chemically reactive?

Accepted Answer

They have unpaired electrons in their valence shell, making them likely to form bonds.

Question 20

Which of the following is a consequence if ice did not float on water?

Accepted Answer

Bodies of water would freeze from the bottom up, threatening aquatic life.

Chapter 2: The Chemical Context of Life – Study Notes

Study Guide - Practice Questions