Question 1

Which of the following best explains why table salt (NaCl) exhibits emergent properties compared to its constituent elements sodium and chlorine?

Accepted Answer

Table salt has properties different from sodium and chlorine because the ionic bond between Na+ and Cl− creates a stable compound with new characteristics.

Question 2

A non-pregnant adult female requires 18 mg of iron per day. If chicken liver contains 11 mg of iron per 100 g, what is the minimum mass of chicken liver she must eat to meet her daily iron requirement? Use the formula $$m = \frac{R}{C} 	imes 100$$ where $$R is $$the required iron (mg) and $$C is $$the iron content per 100 g.

Accepted Answer

163.6 g

Question 3

Which four elements make up about 96% of the weight of most living organisms?

Accepted Answer

Oxygen, Carbon, Hydrogen, Nitrogen

Question 4

What is the atomic number and number of neutrons in the isotope sulfur-34?

Accepted Answer

Atomic number 16, 18 neutrons

Question 5

Why are radioactive isotopes useful as tracers in biological research?

Accepted Answer

They can be detected by sophisticated instruments, allowing scientists to track the movement of atoms in living organisms.

Question 6

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

Accepted Answer

Polar covalent bonds share electrons unequally, resulting in partial charges, while nonpolar covalent bonds share electrons equally.

Question 7

What holds together the ions in a crystal of table salt (NaCl)?

Accepted Answer

Electrostatic attraction between oppositely charged Na+ and Cl− ions

Question 8

Which property of water allows insects like water striders to walk on its surface?

Accepted Answer

Surface tension due to cohesion between water molecules

Question 9

Why does ice float on water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds hold water molecules in a rigid structure with more space between them.

Question 10

What is the role of buffers in biological fluids?

Accepted Answer

Buffers minimize changes in pH by accepting or donating H+ ions.

Question 11

Which equation correctly represents the chemical reaction for the formation of water from hydrogen and oxygen?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O$$

Question 12

Which of the following best explains why blood and most other biological fluids are classified as aqueous solutions?

Accepted Answer

They are mixtures of water and dissolved polar or charged solutes.

Question 13

As atmospheric CO2 increases and dissolves in ocean water, what is the primary effect on coral reefs?

Accepted Answer

The water becomes more acidic, reducing carbonate ion concentration and slowing coral calcification.

Question 14

Which of the following is a trace element commonly added to municipal water to prevent disease?

Accepted Answer

Fluoride

Question 15

Which subatomic particle determines the chemical behavior of an atom?

Accepted Answer

Electron

Question 16

Which property of water is most important for moderating temperature in living organisms?

Accepted Answer

Hydrogen bonds absorb and release heat, stabilizing temperature

Question 17

What is the main reason scientists search for water when looking for extraterrestrial life?

Accepted Answer

Water's emergent properties support life, making it essential for biological processes.

Question 18

Which equation describes the relationship between pH and hydrogen ion concentration?

Accepted Answer

$$pH = -\log_{10}[H^+]$$

Question 19

In a controlled experiment studying coral calcification, what are the independent and dependent variables?

Accepted Answer

Independent: carbonate ion concentration; Dependent: rate of calcification

The Chemical Basis of Life: Elements, Atoms, and Water’s Role in Biology

Study Guide - Practice Questions

Study Guide - Flashcards