Why alkenes are known as olefins?

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Olefins**: The term "olefins" is derived from the Latin word "oleum," which means oil. Therefore, olefins can be understood as "oil-forming" substances.

2. **Characteristics of Alkenes**: Alkenes are hydrocarbons that contain at least one carbon-carbon double bond (C=C). This double bond makes them unsaturated, meaning they have fewer hydrogen atoms than alkanes (which only have single bonds).

3. **First Member of Alkenes**: The simplest alkene is ethylene, also known as ethene (C2H4). It is the first member of the alkene family.

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