Question 1

Which of the following best explains why water has a high specific heat capacity?

Accepted Answer

Hydrogen bonds between water molecules require significant energy to break.

Question 2

A lithium atom has 3 protons and 4 neutrons. What is its atomic mass in daltons?

Accepted Answer

$$7$$

Question 3

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

Accepted Answer

Cohesion due to hydrogen bonding

Question 4

If the pH of a solution changes from 6 to 4, how does the concentration of hydrogen ions ($$[H^+]) $$change?

Accepted Answer

It increases by 100 times

Question 5

Which of the following is NOT an emergent property of water that contributes to Earth's suitability for life?

Accepted Answer

Formation of ionic bonds

Question 6

Which statement best describes the difference between covalent and ionic bonds?

Accepted Answer

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

Question 7

A solution has a pH of 3. How many times more acidic is it than a solution with a pH of 6?

Accepted Answer

$$1000$$ times

Question 8

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

Accepted Answer

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

Question 9

Which subatomic particle determines the chemical behavior of an atom?

Accepted Answer

Electron

Question 10

What would happen to the pH of pure water if you added 0.01 mol of a strong acid?

Accepted Answer

The pH would decrease significantly.

Question 11

Which of the following best describes electronegativity?

Accepted Answer

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

Question 12

Which of the following is a buffer’s primary function in biological systems?

Accepted Answer

To maintain a stable pH by neutralizing acids and bases.

Question 13

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

Accepted Answer

Water’s polarity allows it to surround and separate ions.

Question 14

If a blood sample has a pH of 7.4 and another sample has a pH of 6.4, how many times more hydrogen ions does the second sample contain?

Accepted Answer

$$100$$ times

Question 15

Which of the following is a real-world example of a chemical reaction breaking chemical bonds?

Accepted Answer

Cellular respiration converting glucose and oxygen into carbon dioxide and water

Question 16

Which of the following best describes the role of buffers in human blood?

Accepted Answer

Buffers prevent drastic changes in pH when acids or bases are added.

Question 17

Which of the following is true about isotopes of an element?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 18

Which of the following is a consequence of water’s high heat of vaporization for living organisms?

Accepted Answer

It enables evaporative cooling, helping organisms regulate body temperature.

Question 19

Which of the following best explains why acids have a low pH?

Accepted Answer

They have a high concentration of hydrogen ions ($$[H^+]).$$

Question 20

Which of the following is a direct result of the polarity of water molecules?

Accepted Answer

Water forms hydrogen bonds with other water molecules.

General Biology Study Notes: Chemical Elements, Water, and Life

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