The spin of an entangled electron, like any other electron, can have two possible values: "spin up" or "spin down." These terms refer to the orientation of the electron's intrinsic angular momentum, which is a fundamental property of particles. However, the specific value of the spin for an entangled electron depends on the entangled state in which it is entangled with another particle.
Entanglement is a phenomenon in quantum mechanics where two or more particles become correlated in such a way that their states are inseparable, regardless of the distance between them. When two electrons become entangled, their spins become entangled as well, meaning that the spins of the electrons are dependent on each other.
The entangled state of the electrons can be described by a mathematical equation that represents the superposition of the spin-up and spin-down states of each electron. In this entangled state, the individual spins of the electrons are not well-defined until a measurement is made on one of the entangled electrons, at which point the spins of both electrons become determined instantaneously.
Therefore, the specific value of the spin for an entangled electron is not fixed until it is measured, and the result of the measurement is random and probabilistic.