Question 1

Which subatomic particle determines the atomic number of an element and is responsible for its chemical identity?

Accepted Answer

Proton

Question 2

A radioactive isotope of carbon, $$^{14}C$$, is commonly used in biological research. What property makes $$^{14}C$$ useful for tracing metabolic pathways?

Accepted Answer

It can be detected due to its radioactive decay

Question 3

Why do elements in the same group of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons

Question 4

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is a group of atoms bonded together, while a compound is a molecule made of different elements

Question 5

Which bond type is formed by the complete transfer of electrons from one atom to another?

Accepted Answer

Ionic bond

Question 6

Water has a high heat capacity. Which property of water molecules is primarily responsible for this?

Accepted Answer

The extensive hydrogen bonding between molecules

Question 7

Hydrogen bonds in water arise due to which property?

Accepted Answer

The polarity of water molecules

Question 8

Why are hydrogen bonds biologically important?

Accepted Answer

They stabilize the structure of proteins and DNA

Question 9

How does molecular polarity influence the solubility of a substance in water?

Accepted Answer

Polar molecules dissolve well in water due to hydrogen bonding

Question 10

Which equation represents the dissociation of a weak acid in water, such as acetic acid?

Accepted Answer

$$\mathrm{CH_3COOH} \rightarrow \mathrm{CH_3COO^-} + \mathrm{H^+}$$

Question 11

Buffers are important in biological systems because they:

Accepted Answer

Maintain a stable pH by neutralizing acids and bases

Question 12

Which of the following best describes capillary action?

Accepted Answer

The movement of water against gravity due to cohesion and adhesion

Question 13

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

Accepted Answer

High surface tension due to hydrogen bonding

Question 14

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$the solution?

Accepted Answer

$$1 	imes 10$$^{-4}$$ M

Question 15

Which of the following is an example of a buffer system in human blood?

Accepted Answer

Bicarbonate-carbonic acid system

Question 16

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

Accepted Answer

Its high heat capacity

Question 17

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

Accepted Answer

Hydrogen bonds in ice create an open lattice structure

Question 18

Which of the following is NOT a unique property of water?

Accepted Answer

Ability to dissolve nonpolar molecules

Question 19

A scientist adds a strong acid to a buffered solution. What will happen to the pH?

Accepted Answer

The pH will remain relatively stable

Question 20

Which of the following best describes the role of valence electrons in chemical bonding?

Accepted Answer

They are responsible for the formation of chemical bonds

Fundamental Chemical Principles for Microbiology

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