Draw the Lewis Structure of C2H4 and Identify Its Geometry

To draw the Lewis structure of C₂H₄ (ethylene), follow these steps:

1. Count the total number of valence electrons: Carbon has 4 valence electrons, and hydrogen has 1. For C₂H₄, there are 2 carbon atoms and 4 hydrogen atoms. So, the total number of valence electrons is (2 × 4) + (4 × 1) = 12.
2. Draw the skeletal structure: Place the two carbon atoms in the center and arrange the hydrogen atoms around them. Each carbon atom will be bonded to two hydrogen atoms.
3. Distribute the electrons: Start by forming single bonds between the carbon atoms and the hydrogen atoms. This uses up 8 electrons (4 single bonds × 2 electrons each). You will have 4 electrons left.
4. Form a double bond between the carbon atoms: Use the remaining 4 electrons to form a double bond between the two carbon atoms. This completes the octet for each carbon atom.

The Lewis structure of C₂H₄ looks like this:

    H   H
    |   |
H—C=C—H
    |   |
    H   H

Geometry: The geometry of C₂H₄ is planar. Each carbon atom is sp² hybridized, meaning they have three regions of electron density (one double bond and two single bonds). This results in a trigonal planar geometry around each carbon atom, with bond angles of approximately 120°.