Question

When rubidium ions are heated to a high temperature, two lines are observed in its line spectrum at wavelengths (a) 7.9 × 10−7 m and (b) 4.2 × 10−7 m. What are the frequencies of the two lines? What color do we see when we heat a rubidium compound?

Answer 1

Answer:

The frequencies of the two lines are:

a) $3.79\times 10^{14} s^{-1}$

b)$7.14\times 10^{14} s^{-1}$

When we heat rubidium compound we will see red color.

Explanation:

$\nu=\frac{c}{\lambda }$

c = speed of light

$\lambda$ = wavelength of light

a) Frequency of the light when wavelength is equal to $7.9\times 10^{-7} m$

$\nu=\frac{c}{\lambda }$

$\nu=\frac{3\times 10^8m/s)}{7.9\times 10^{-7}}$

$\nu=3.79\times 10^{14} s^{-1}$

This frequency corresponds to red light

b) Frequency of the light when wavelength is equal to $4.2\times 10^{-7} m$

$\nu=\frac{c}{\lambda }$

$\nu=\frac{3\times 10^8m/s)}{4.2\times 10^{-7}}$

$\nu=7.14\times 10^{14} s^{-1}$

This frequency corresponds to violet light

When we heat rubidium compound we will see red color.