Understanding scala binary compatibility on my example

Question

I have some scala program which uses spark-2.4.6 framework. My code is compiled with scala-2.12.12.

1. How can I check if my code (compiled to class files) is compatible with spark-2.4.6?
2. How can I check what version of scala compiler is used to build class of spark?
3. What does it mean binary compatibility here? Is there exists list of compatible scala compilers?

Answer 1

https://spark.apache.org/docs/2.4.4/ Look at the docs per version. It states the scala versions needed.