How can you ensure that the particle has already been entangled?

[Hououin Kyouma]

There are several questions I am wondering.
1. If I give you a particle, how can you ensure that the particle has already been entangled?
2. If I give you a pair of particles, how can you ensure that these particles have already been entangled?

In how many ways, e.g. in the theoretical/mathematical method can be used to solve the problem?

Thank you all for answering.

 

[Demystifier]

If you give me one or two particles and don't tell me how did you prepared them, then I cannot determine that they are entangled. However, if you give me many particles, or many pairs of particles, which are all prepared in the same way, then I can determine whether they are entangled. The more particles you give me, I can determine it with better certainty.

 

[FX_physics]

There are several questions I am wondering.
1. If I give you a particle, how can you ensure that the particle has already been entangled?
2. If I give you a pair of particles, how can you ensure that these particles have already been entangled?

In how many ways, e.g. in the theoretical/mathematical method can be used to solve the problem?

Thank you all for answering.

If an electron at a higher energy level, it downward transition twice and emit one photon at each downward transition, the two photons created this way entangled each other , their spins always opposite.