xDAI blockchain properties

Dear xDAI Team,

I am collecting these data for a study comparing performances of EVM compatible blockchains.
I have a few questions regarding the xDAI blockchain properties in terms of scalability, decentralization, and security.

Could you please provide me with some answers on the below questions:

  1. Scalability: How much transactions per second (TPS) can xDAI process?
  2. Decentralization: How many nodes (validators) is there for the xDAI blockchain network?
  3. Security: What is the cost to attack the xDAI blockchain? (are we talking about a 51% attack or 33% attack?)

Thank you in advance.