Are processors interchangeable

Answer 1

Each motherboard is Chip specific. If your motherboard is for an AMD then you will only be able to use AMD processors in it. If you want change your Processor then you would have to get the right motherboard for that processor.

Answer

Processors (regardless of who makes them) have a set of electrical and communications standards which they use, and a physical design of the package. Processors which have the identical package, electrical characteristics, and bus communication standards can be interchanged with each other (provided the BIOS or PROM can properly understand the identity value the CPU has).

For a variety of reasons, mostly related to patents, interchangability these days (post 2005) is limited to processors from a single manufacturer, and within a "family".

Ultimately, you will have to refer to the MOTHERBOARD manufacturer's documentation to find out which CPUs can be used in that particular system.