Question 1

Which of the following best describes the relationship between atomic number and the identity of an element?

Accepted Answer

The atomic number is equal to the number of protons, which determines the element.

Question 2

A sodium atom (Na) has 11 protons and 11 electrons. If it loses one electron to form a sodium ion (Na⁺), what is the resulting charge and why?

Accepted Answer

The sodium ion has a positive charge because it lost an electron.

Question 3

Which of the following best explains why water (H$$_2O) is a $$polar molecule?

Accepted Answer

Oxygen has a stronger pull on shared electrons, resulting in unequal sharing and partial charges.

Question 4

Which of the following is a correct statement about the octet rule?

Accepted Answer

Atoms are most stable when they have eight electrons in their valence shell, except for hydrogen and helium.

Question 5

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electron pairs between atoms.

Question 6

A solution with a pH of 4 has how many times more hydrogen ions (H$$^+) $$than a solution with a pH of 7?

Accepted Answer

$$1000$$ times more

Question 7

Which of the following is a function of enzymes in the human body?

Accepted Answer

Enzymes act as catalysts to speed up chemical reactions by lowering activation energy.

Question 8

Which of the following best distinguishes organic from inorganic compounds?

Accepted Answer

Organic compounds contain carbon-hydrogen (C-H) bonds, while inorganic compounds typically do not.

Question 9

Which of the following is the primary function of carbohydrates in the human body?

Accepted Answer

To provide a primary source of energy

Question 10

Which of the following best describes the structure of a triglyceride?

Accepted Answer

A molecule composed of one glycerol molecule and three fatty acids

Question 11

Which of the following statements about proteins is correct?

Accepted Answer

Proteins are made up of amino acids linked by peptide bonds.

Question 12

Which of the following is a correct pairing of a macromolecule and its monomer?

Accepted Answer

Nucleic acid – nucleotide

Question 13

Which of the following best explains why phospholipids are essential for cell membrane structure?

Accepted Answer

They have both hydrophilic heads and hydrophobic tails, allowing them to form bilayers in water.

Question 14

A patient’s blood pH is measured at 7.2. Which of the following best describes this condition?

Accepted Answer

The patient is experiencing acidosis.

Question 15

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Unsaturated fatty acids have one or more double bonds between carbon atoms, while saturated fatty acids have only single bonds.

Question 16

Which of the following is a function of ATP in the cell?

Accepted Answer

ATP provides energy for cellular processes by releasing a phosphate group.

Question 17

Which of the following best describes the role of catabolic reactions in the body?

Accepted Answer

Catabolic reactions break down large molecules into smaller ones and release energy.

Question 18

Which of the following is true about the structure of DNA?

Accepted Answer

DNA is a double-stranded molecule with paired strands coiled into a double helix.

Question 19

Which of the following best explains why enzymes are specific to particular reactions?

Accepted Answer

Enzymes have unique three-dimensional shapes that fit only specific substrates.

Question 20

A molecule of glucose (C$$_6H$_{12}O$_6) is $$classified as which of the following?

Accepted Answer

A monosaccharide and a monomer of carbohydrates

Chapter 2: The Chemistry of Life – Chemical Level of Organization

Study Guide - Practice Questions