Bohr Formula

[tessadalke]

Could someone explain to me when I would use hR/n^2?

[Douglas Nguyen 2J]

Could someone explain to me when I would use hR/n^2?

You would use the that formula, which is exclusive to hydrogen atoms, when attempting to calculate energy levels or energy output. A few of the questions in the textbook use this formula as a means to eventually find the energy to find the wavelength or frequency of the incoming photon.

E(n)=-hR/n^2
h is Planck's constant (6.6262 x 10^-34 Js), and R is Rydberg's constant (3.29 x 10^15). n represents the energy level.

[105114680]

Use the formula when you are asked to calculate an electron's change in energy when it transitions from different energy levels (e.g. n=4 to n=2). You can also use the change in energy to calculate the frequency and wavelength of the light emitted due to the loss of energy when an electron transitions to a lower energy level (since the decrease in energy is released as EM radiation).

[rkang00]

Why do we have to add a negative sign though? is it just an indication of a difference in energy levels?

[Jaqueline Monreal 2L]

theres a negative number to show that when the energy levels decrease, energy is lost , so the calculated energy using this formula will be negative