An aldehyde as well as a ketone can be represented by the same molecular formula, say $C_3H_6O$. Write their structures and name them. State the relation between the two in the language of science.

For the molecular formula $\text{C}_3 ext{H}_6 ext{O}$, the two functional group representations are:

1. Aldehyde:

• Name: Propanal
• Structure:

$$\text{CH}_3-\text{CH}_2-\text{CHO}$$

(Or structurally represented as:)

$$\text{H}-\overset{\begin{matrix}\text{H}\\\|\end{matrix}}{\underset{\begin{matrix}|\\\text{H}\end{matrix}}{\text{C}}}-\overset{\begin{matrix}\text{H}\\\|\end{matrix}}{\underset{\begin{matrix}|\\\text{H}\end{matrix}}{\text{C}}}-\overset{\begin{matrix}\text{O}\\\|\!\|\end{matrix}}{\text{C}}-\text{H}$$

1. Ketone:

• Name: Propanone (commonly known as acetone)
• Structure:

$$\text{CH}_3-\text{CO}-\text{CH}_3$$

(Or structurally represented as:)

$$\text{H}-\overset{\begin{matrix}\text{H}\\\|\end{matrix}}{\underset{\begin{matrix}|\\\text{H}\end{matrix}}{\text{C}}}-\overset{\begin{matrix}\text{O}\\\|\!\|\end{matrix}}{\text{C}}-\overset{\begin{matrix}\text{H}\\\|\end{matrix}}{\underset{\begin{matrix}|\\\text{H}\end{matrix}}{\text{C}}}-\text{H}$$

Relation in the language of science:

These two compounds are structural isomers (specifically functional isomers). They share the same molecular formula ($\text{C}_3 ext{H}_6 ext{O}$) but possess different functional groups (an aldehyde group $-\text{CHO}$ in propanal, and a ketone group $-\text{CO}-$ in propanone), which gives them distinct chemical and physical properties.