What type of bond is formed between two carbon atoms in an alkene?

In an alkene, a double bond is formed between two carbon atoms. Alkenes are hydrocarbons that contain at least one carbon-carbon double bond, which consists of one sigma (σ) bond and one pi (π) bond. The sigma bond is formed by the head-on overlap of atomic orbitals, while the pi bond results from the sideways overlap of p orbitals. This configuration allows for the characteristic reactivity of alkenes, making them more reactive than alkanes, which only have single bonds. The presence of the double bond also introduces geometric isomerism, as the restricted rotation around the double bond can lead to different spatial arrangements of substituents on the carbon atoms, further defining their chemical behavior.