Constants
Topics:
Values
Energy
Equivalents
Searchable
Bibliography
Background
Constants
Bibliography
Constants,
Units &
Uncertainty
home page
Correlation coefficient between two constants
alpha particle-proton mass ratio
Numerical value
3.972 599 690 252
Standard uncertainty
0.000 000 000 070
Relative standard uncertainty
1.8 x 10
-11
Concise form
3.972 599 690 252(70)
Source: 2022 CODATA
recommended values
Definition of
uncertainty
Correlation coefficient with
any other constant
 
Select the
second
constant in the pair
(e.g,
electron mass
, misspellings okay)
Search
by name
Or
browse the complete constants list
Click
here
to re-select the
first
constant