Answer:
The kilogram is the standard unit of mass.
In a titration process, the unknown or the analyte with a known volume is placed in a flask and the titrant whose concentration is known is placed in the burette. The indicator in the titration process is generally added to the flask with the analyte.
Knees and elbows are two of the most common ones.
I want to say physical change? i’m not quite sure, i hope this helps tho!