Question 1

Which of the following best describes an emergent property of a compound?

Accepted Answer

A property that arises only when two or more elements combine in a fixed ratio, resulting in characteristics different from the individual elements.

Question 2

A patient is diagnosed with goiter, a swelling of the thyroid gland. Which trace element deficiency is most likely responsible for this condition?

Accepted Answer

Iodine (I)

Question 3

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 4

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

Accepted Answer

$$23 - 11 = 12$$

Question 5

Which of the following best explains why water is an effective solvent for ionic compounds?

Accepted Answer

Water molecules are polar, allowing them to surround and separate ions due to their partial charges.

Question 6

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 7

A gecko can walk up walls due to the combined effect of many weak interactions between its toe pads and the wall. What type of interaction is primarily responsible for this phenomenon?

Accepted Answer

Van der Waals interactions

Question 8

Which of the following best describes the difference between cohesion and adhesion in water?

Accepted Answer

Cohesion is the attraction between water molecules; adhesion is the attraction between water molecules and other substances.

Question 9

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

Accepted Answer

$$6 CO_2$ + 6 H_2O \xrightarrow{sunlight} C_6H_{12}O_6$ + 6 O_2$

Question 10

Which property of water allows it to moderate temperature in living organisms?

Accepted Answer

High specific heat

Question 11

A solution has a pH of 4. How does its hydrogen ion concentration $$[H^+]$$ compare to a solution with a pH of 7?

Accepted Answer

It is 1,000 times higher.

Question 12

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

Accepted Answer

Ice is less dense than liquid water because its hydrogen bonds keep water molecules farther apart.

Question 13

Which of the following is a trace element required by humans and a deficiency of which can cause disease?

Accepted Answer

Iodine (I)

Question 14

Which of the following statements about ionic bonds is correct?

Accepted Answer

Ionic bonds result from the transfer of electrons from one atom to another, creating oppositely charged ions.

Question 15

A radioactive isotope is used in a PET scan to trace metabolic processes. What property of radioactive isotopes makes this possible?

Accepted Answer

They emit energy as they decay, which can be detected by imaging equipment.

Question 16

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

Accepted Answer

A substance that minimizes changes in pH by accepting or donating $$H^+$$ ions.

Question 17

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 nucleus.

Question 18

Which of the following best explains why sodium (Na) and chlorine (Cl) form an ionic bond to create sodium chloride (NaCl)?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions that attract each other.

Question 19

Which of the following is a real-world example of an organism adapting to tolerate toxic elements?

Accepted Answer

A plant species that can grow in soils contaminated with high levels of lead and zinc.

Question 20

Which of the following best describes the relationship between atomic mass and mass number?

Accepted Answer

Mass number is the sum of protons and neutrons, while atomic mass is the weighted average of all isotopes.

Chapter 2: The Chemical Context of Life – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard