Why are carbocations positive?
Because that's how they were defined. Cations are positively-charged, so carbocations are positively-charged carbons.
Carbocation stability goes like this:
- They form when a leaving group leaves, taking its bonding pair of electrons with it.
- Assuming an ideal covalent bond, the to-be-formed carbocation would evenly share 1 electron with the rest of the molecule.
When the leaving group leaves, the carbon therefore has a net loss of 1 electron, giving the carbon in the carbocation a