Why do electrons have spin quantum numbers of +1/2 and -1/2?

[Stephen Raj]

According to spin quantum number, the spin value of electron pair is taken as +1/2 and -1/2.
Why should we take only these values. I didn't understand what the spin of electron represents.

 

[Vanadium 50]

How much quantum mechanics do you know? It will make it easier for the answer to be at an understandable level.

 

[Eynstone]

Please have a look at Dirac's equation.

 

[guerom00]

According to spin quantum number, the spin value of electron pair is taken as +1/2 and -1/2.

The value 1/2 for the spin of the electron is just an intrinsic property of this particle like, say, its mass.
Your question could have been “Why is the electric charge of the electron -1 ?”