# Hybridization in ethene [closed]

I recently learned that there is such thing as a hybridization in chemistry, but I don't really get it.

For example, in $$\ce{C2H2}$$ (Ethene), they say the there are 3 electrons in three $${sp^2}$$ and one electron in a normal $$p$$ orbital. How do we decide what orbitals get hybridized and what doesn't?

• Welcome to ChemSE. Please keep in mind that the concept of hybridization you mention here applies on atomic, and eventually on molecular orbitals; and not on electrons. – Buttonwood Oct 8 '18 at 21:15

When a carbon is involved in single bonds only, its $${s}$$- and three $${p}$$-orbitals are $${sp^3}$$-hybridized. When a carbon is involved in a double bond (alkenes, carbonyls etc.), three of four orbitals are $${sp^2}$$-hybridized, because the double bond consists of one $$\pi$$-bond and one $$\sigma$$-bond. When a carbon is involved in a triple bond (alkynes, nitriles etc.) two of four orbitals are $${sp}$$-hybridized, because the triple bond consists of two $$\pi$$-bonds and one $$\sigma$$-bond.