Question

The frequency of radiation absorbed or emitted when transition occurs between two stationary states with energies $E_1$ (lower) and $E_2$ (higher) is given by

• A. $\upsilon=\frac{E_{1}+E_{2}}{h}$
• B. $\upsilon=\frac{E_{1}-E_{2}}{h}$
• C. $\upsilon=\frac{E_{1} \times E_{2}}{h}$
• D. $\upsilon=\frac{E_{2} - E_{1}}{h}$

Answer 1

Answer: (D)

According to Bohr's postulates:
The frequency of radiation absorbed or emitted when transition occurs between two stationary states that differ in energy by $\Delta E$, is given by:
$v=\frac{\Delta E}{h}=\frac{E_{2}-E_{1}}{h}$
Where $E _{1}$ and $E _{2}$ are the energies of the lower and higher allowed energy states, respectively.
This expression is commonly known as Bohr's frequency rule.