To determine the size amp brkr. For a 5kw a/c unit do I just divide 238 (v.) by 5000

What does the rating plate say?

Where are you getting the 5kW number from? A/C's are not typically rating in wattage.

I'm referring to language in the recent past
With heat pump and air handler/heater... when changing out old system which was not a heat pump and they said heat strip was only 5kw in new unit which brings me to the next question, how do you
Tell a heat pump from a regular compressor aside from looking at thermostat and seeing emergency heat

Strip heat is NOT A/C. Not even close. Two completely different animals.

A/C or heat pump condensers are the outside unit of a split system. Strip heat goes inside the air handler and is above and beyond all the other parts of the system.
Meaning for example if the AH draws 2A @ 240v, and the condenser draws 20A @ 240v, 5000 watts of electric heat would draw an additional 21A @ 240v, but would be wired with the AH.
Condensers are wired separately, but joined by a control wire.

I don't know how to tell a heat pump just by looking at the unit. I would have to read the plate.

Thank you for your expertise and just to confirm... to tell if the outside unit is a compressosr or heat pump, look at the spec. label?