> i have found a PowerMac G5 2.0GHZ mono-processor and i would
> like to know if it compatible with MorphOS ? It's a PowerMac 7.2

According to http://www.morphos-team.net/hardware, MorphOS is compatible with PowerMac7,2 in general, no matter the CPU count. After all, it wouldn‘t make sense for a single-processing OS to require the presence of multiple CPUs.
What‘s strange though is that I don‘t think there ever was a single-CPU PowerMac7,2 at 2.0 GHz. Single-CPU goes up to 1.8 GHz only. Maybe it‘s overclocked 1.8 GHz model (if even possible), or 2.0 GHz model with one CPU broken/removed?