Moseley's Law
An empirical law establishing a linear relationship between the square root of characteristic X-ray frequency emitted by an atom and its atomic number Z.
Governing formula
√ν = A (Z - b)
SI unit
Hz^(1/2) (Frequency Square Root)
In depth
Discovered by Henry Moseley in 1913, this law proved that atomic properties are governed by nuclear charge Z (atomic number) rather than atomic mass, reordering the Periodic Table correctly.
Examples in the real world
Identifying unknown elements and confirming atomic numbers of elements using characteristic K-alpha X-ray spectroscopy.