Question

An iconic atom equivalent to hydrogen atom has a wavelength equal to $\frac{1}{4}$ of the wavelength of hydrogen lines. The ion will be

• A. $H{e}^{+}$
• B. $L{i}^{+}+$
• C. $N{e}^9+$
• D. $N{a}^{10+}$

Answer 1

The correct option is A $H{e}^{+}$

$\overline{v}\propto \frac{1}{\lambda }\propto Z^2$

$\Rightarrow \lambda Z^2=constant$

$\Rightarrow \lambda =\frac{\lambda }{4}{Z}^2$

$\Rightarrow Z=2$