What are alkenes and alkynes?

Hidrocarbons that have a pi bond (π), that is, a double bond (- C = C -) or a triple bond (- C Ξ C -).
They are called unsaturated because they give addition reactions with pi bond rupture, which is the zone of high reactivity in the molecule.
Alkenes or olefins: CnH2n and n > 1.
They have a lower number of hydrogen atoms than alkanes with the same number of carbons.
The carbon atoms joined by the double bond have 3 sp2 hybrid orbitals, each of which forms a sigma (σ) bond, which are located in the same plane at an angle of 120°. The unhybridized 'p' orbital is arranged perpendicular to the plane, forming a pi (π) bond.
Their most important chemical reactions are addition and polymerization.