Remove the units from Physical Constants Package

Questions
,
1

In Physical Constants Package (I know it’s obsolete now, still handy) when I call a constant and do some manipulations I am left with something that has units attached to it. How can I remove this units part leaving just the number? Thanks.

2

The best choice to do what you want is by using the functions Quantity, UnitConvert and QuantityMagnitude.

UnitConvert@Quantity["ProtonMass"]
QuantityMagnitude@%

If you do not want or cannot use them for some reason, one possible way to get the numerical value from the measurement is by using Part or First.

Off[General::obspkg]
<< PhysicalConstants`

ProtonMass
%[[1]]
%% // First
3

Thanks, that works.