Which of the statements correctly describes cis isomers?

The carbon chain enters and leaves the single bond on opposite sides of the molecule.

The carbon chain enters and leaves the single bond on the same side of the molecule.

The carbon chain enters and leaves the double bond on opposite sides of the molecule.

The carbon chain enters and leaves the double bond on the same side of the molecule.

Well, if we're talking about cis isomers, it means the carbon chain enters and leaves the double bond on the same side of the molecule. They like to stick together, just like two peas in a pod! So, the correct statement is: The carbon chain enters and leaves the double bond on the same side of the molecule.

To determine which statement correctly describes cis isomers, we need to understand the concept of cis isomerism in organic chemistry.

Cis isomerism is a type of geometric isomerism that occurs when two identical groups or atoms are located on the same side of a molecule, either around a double bond or a ring structure. It is the opposite of trans isomerism, where the groups or atoms are located on opposite sides.

Looking at the statements provided:

1. "The carbon chain enters and leaves the single bond on opposite sides of the molecule." This statement does not accurately describe cis isomers. It is more aligned with trans isomerism, where the groups or atoms are on opposite sides.

2. "The carbon chain enters and leaves the single bond on the same side of the molecule." This statement correctly describes cis isomers. In cis isomerism, the carbon chain enters and leaves a single bond (such as in a double bond) on the same side of the molecule.

3. "The carbon chain enters and leaves the double bond on opposite sides of the molecule." This statement does not accurately describe cis isomers. It is more aligned with trans isomerism, where the groups or atoms are on opposite sides.

4. "The carbon chain enters and leaves the double bond on the same side of the molecule." This statement does not accurately describe cis isomers. It is similar to the second statement but specifically refers to double bonds.

Therefore, the correct statement that describes cis isomers is: "The carbon chain enters and leaves the single bond on the same side of the molecule."