Henry Moseley

• In 1913, Henry Moseley, an English physicist, while working for Ernest Rutherford, was able

  to develop the concept of the atomic number, a whole number to the size of the nuclear charge of an

  atom.
• Moseley

  was able to solve the irregularities in Mendeleev’s periodic table.
• Moseley concluded that it is better

  to explain the trends in Mendeleev’s table if the elements were arranged according to increasing

  atomic number.
• Moseley then stated that atomic number is the most fundamental property of an element

  and not its atomic mass.
• Mendeleev said, ''the chemical and physical properties of elements are a periodic function of their atomic number