$$\text{Atomic mass} = \text{Number of protons} + \text{Number of neutrons} + \text{Number of electrons}$$

Question 1

Which of the following best describes an atom?

Accepted Answer

The smallest chemical unit of matter

Question 2

What is the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 3

Which subatomic particle is responsible for the chemical behavior of an atom?

Accepted Answer

Electrons

Question 4

Carbon-14 is an example of a radioactive isotope. What makes it radioactive?

Accepted Answer

It has an unstable nucleus that releases energy during decay

Question 5

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons determine the atom's chemical behavior

Question 6

A molecule of sodium chloride (NaCl) is formed by which type of chemical bond?

Accepted Answer

Ionic bond

Question 7

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

Accepted Answer

Water molecules have two polar covalent bonds, allowing them to interact with many substances

Question 8

What is the main difference between a molecule and a compound?

Accepted Answer

A compound is a molecule composed of more than one element

Question 9

Which of the following is a property of acids when dissolved in water?

Accepted Answer

They dissociate into one or more H$$^+$$ ions and one or more anions

Question 10

Which equation correctly represents the relationship between atomic mass and subatomic particles?

Accepted Answer

$$	ext{Atomic mass} = 	ext{Number of protons} + 	ext{Number of neutrons} + 	ext{Number of electrons}$$

Question 11

Which type of chemical reaction is described as endothermic and involves the formation of larger, more complex molecules?

Accepted Answer

Synthesis reaction

Question 12

What is the function of buffers in biological systems?

Accepted Answer

To prevent drastic changes in internal pH

Question 13

Which of the following is NOT a function of carbohydrates in cells?

Accepted Answer

Catalyzing chemical reactions

Question 14

Which macromolecule is NOT composed of regular subunits and is hydrophobic?

Accepted Answer

Lipids

Question 15

Which of the following is true about phospholipids?

Accepted Answer

They have both hydrophilic and hydrophobic regions

Question 16

Which type of bond is responsible for stabilizing the 3-D shapes of large biological molecules such as proteins and DNA?

Accepted Answer

Hydrogen bonds

Question 17

Which of the following statements about nucleic acids is correct?

Accepted Answer

DNA carries instructions for synthesis of RNA and proteins

Question 18

Which of the following correctly describes a peptide bond?

Accepted Answer

A covalent bond formed between two amino acids

Question 19

Which of the following is a correct statement about exchange reactions?

Accepted Answer

They involve both breaking and forming covalent bonds

Question 20

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

Accepted Answer

Three hydrogen bonds form between cytosine and guanine

CH 2. The Chemistry of Microbiology: Foundations for College Microbiology

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