Atomic number (Moseley's law)
Número atómico como base de la ley periódica
- Date
- 1913-1914 · confidence high
- Place
- University of Manchester and Oxford, England
- Credited to
- Henry Moseley
- People
- 👤 Henry Moseley.1887–1915
- Field
- Matter & energy
What was discovered
The frequency of each element's characteristic X-rays varies with the square of an integer, the atomic number (nuclear charge). It orders the periodic table by Z, resolves the atomic-weight inversions and fixes how many elements are missing.
Van den Broek had suggested in 1911 that Z was the nuclear charge; Moseley proved it. He died at Gallipoli in 1915.
What it led to
- Definitive periodic table
- Identification of missing elements (43, 61, 72, 75)
- X-ray fluorescence analysis
Built on
- X-ray diffraction (crystallography)1912–1913
- Rutherford's nuclear model
Made possible
- Hafnium1923
- Rhenium1925
- X-ray fluorescence spectrometry