Question 1

Which of the following statements best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

Which type of chemical bond is the strongest under physiological conditions?

Accepted Answer

Covalent bond

Question 3

A solution has a pH of 4. What is the hydrogen ion concentration relative to a solution with pH 7?

Accepted Answer

It is 1000 times higher.

Question 4

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

Accepted Answer

Oxygen attracts electrons more strongly, creating partial charges.

Question 5

Which of the following ions is most important for nerve impulse transmission in humans?

Accepted Answer

Potassium $$(K^{+})$$

Question 6

What is the main function of buffers in biological systems?

Accepted Answer

To maintain a stable pH by absorbing $$H^{+} or$$ $$OH^{-}$$ ions.

Question 7

Which of the following is a correct chemical notation for a molecule containing two hydrogen atoms and one oxygen atom?

Accepted Answer

$$H_2O$$

Question 8

A patient is given an intravenous solution that is isotonic to their blood cells. What will happen to the cells?

Accepted Answer

There will be no net movement of water.

Question 9

Which of the following best describes a dehydration synthesis reaction?

Accepted Answer

Two small molecules combine to form a larger molecule, releasing water.

Question 10

Which of the following is a real-life application of radioactive isotopes in medicine?

Accepted Answer

They are used to label and track molecules in the body for diagnostic imaging.

Question 11

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

Accepted Answer

A cation is positively charged, while an anion is negatively charged.

Question 12

Which of the following is an example of a polar covalent bond?

Accepted Answer

The bond between hydrogen and oxygen in $$H_2O$$

Question 13

Which of the following best explains why sodium chloride ($$NaCl) $$dissolves easily in water?

Accepted Answer

Water's polarity allows it to surround and separate the ions.

Question 14

Which of the following is a correct statement about oxidation-reduction (redox) reactions?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 15

A solution with a high concentration of $$OH^-$$ ions and a pH of 13 is best described as:

Accepted Answer

Strongly basic (alkaline)

Question 16

Which of the following best describes the role of nitrogen fixation in the environment?

Accepted Answer

It converts nitrogen gas into ammonia and other compounds usable by living organisms.

Question 17

Which of the following is a property of water that is essential for life?

Accepted Answer

It forms hydrogen bonds, allowing for cohesion and temperature regulation.

Question 18

Which of the following best describes a hypertonic solution's effect on a cell?

Accepted Answer

Water moves out of the cell, causing it to shrink.

Question 19

Which of the following is a correct example of a salt formed by an acid-base reaction?

Accepted Answer

$$NaCl$$ formed from $$HCl$$ and $$NaOH$$

Question 20

Which of the following best describes the difference between a synthesis (dehydration) and a hydrolysis reaction?

Accepted Answer

Synthesis reactions build larger molecules by removing water, while hydrolysis breaks down molecules using water.

Chemistry of Life: Atoms, Elements, Bonds, and Water

Study Guide - Practice Questions