Question

In 1913, Moseley discovered the relationship between the X-ray spectra frequency and the atomic number of elements. If we draw a curve between the X-ray frequency $\left(\sqrt{\nu }\right)$ and the atomic number $\left(Z\right)$, it will be a:

• A. Parabola
• B. Hyperbola
• C. Straight line
• D. Rectangular Hyperbola

Answer 1

The correct option is C Straight line

According to Moseley, frequency $\left(\nu \right)$ of X-rays emitted by an element was related to its atomic number $\left(Z\right)$ using the following equation:
$\sqrt{\nu }=a(Z-b)$
[where $a$ and $b$ are constants]
$\sqrt{\nu }=aZ-ab$ ..........(1)
By comparing equation (1) with the straight line equation, $y=mx+c$,
It can be predicted that it will be a straight line with slope '$a$' and y-intercept '$-ab$'.