Why are some of the carbon compounds saturated while others are unsaturated compounds?

Explanation

### Step-by-Step Solution:

1. **Definition of Saturated Compounds**: Saturated compounds are those in which carbon atoms are connected by single bonds only. This means that each carbon atom is bonded to as many hydrogen atoms as possible, fulfilling the tetravalency of carbon (which can form four bonds). An example of a saturated compound is ethane (C2H6), where each carbon is connected to other carbons and hydrogens through single bonds.

2. **Definition of Unsaturated Compounds**: Unsaturated compounds contain at least one double bond (C=C) or triple bond (C≡C) between carbon atoms. This means that not all valencies of carbon are satisfied with hydrogen atoms, allowing for the potential to add more atoms. For example, ethene (C2H4) has a double bond between the two carbon atoms, making it unsaturated.

3. **Reason for Saturation and Unsaturation**: The distinction between saturated and unsaturated compounds arises from the type of bonding between carbon atoms. In saturated compounds, the presence of only single bonds means that the carbon atoms are fully "saturated" with hydrogen atoms. In contrast, unsaturated compounds have double or triple bonds, which means that they can react with additional atoms (like hydrogen) to become saturated.

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