Question

State Moseley's law. Write its equation.

Answer 1

Hint: In this solution, Moseley’s law states that that the square root of the generated x-ray
frequency is equal to the atomic number.
Complete step-by-step answer:

Moseley's law is an empirical law referring to the characteristic x-rays that atoms emit. The rule
was discovered in 1913-1914 by the English physicist Henry Moseley and published there.
Before Moseley’s work, "atomic number" was merely the position of an element in the periodic
table, and was not considered to be correlated with any observable physical quantity. In short, the
law states that the square root of the frequency of the x-ray emitted is approximately proportional
to the atomic number.
By-atomic weight, the traditional periodic table was loosely ordered, but in some popular cases
the physical properties of two elements indicated that the heavier would precede the lighter one.
One example is cobalt weighing 58.9, and nickel weighing 58.7 atomically. Henry Moseley and
other physicists used x-ray diffraction to research the elements, and their experimental findings
contributed to proton count organization of the periodic table.
Moseley’s law:
It states that the spectral line frequency in the characteristic X-ray spectrum is directly
proportional to the square of the element being called atomic number (Z).
Moseley’s equation is,
$v \propto Z2\;\left( {or} \right)\;v\, = a(Z - b)$
Where, a and b are constants depending on the given spectral line.
Note: In Mendeleev's periodic table, Moseley used his rule to organize K and Ar, Ni and CO in a
proper manner. Moseley's law is a law referring to the characteristic x-rays that atoms emit.
Importance: The theorem of Moseley not only defined the atomic number as an observable
experimental quantity, but also gave it a physical sense as the atomic nucleus' positive charge.