Which of the following are alkenes?
`CH_4,C_2H_4,C_2H_6,C_3H_4,C_3H_6`

Explanation

To determine which of the given compounds are alkenes, we need to understand the general formula for alkenes and how to identify them based on their molecular formulas.

### Step-by-Step Solution:

1. **Understand the General Formula for Alkenes:**
Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. The general formula for alkenes is \( C_nH_{2n} \), where \( n \) is the number of carbon atoms.

2. **List the Given Compounds:**
...