Energy change chemistry

Question

A He+ ion in the n = 2 energy state absorbs a photon with a wavelength of 109 nm.

A. What is the energy change (in J) for the He+ ion undergoing the emission? (4)

energy change (J): _______________

B. What are the possible energy states for the He+ ion after the absorption? Explain your

answer. (3)

Answer 1

E = hc/λ

E = energy of photon = ?

h = Planck's constant = 6.626x10^-34 J-sec

c = speed of light = 3x10⁸ m/sec

λ = wavelength = 109 nm = 109x10^-9 m = 1.09x10^-7 m

E = (6.626x10^-24 J-sec)(3x10⁸ m/sec)/1.09x10^-7 m

E = 1.82x10^-8 J

1/λ = RZ² (1/n_f² - 1/n_i²)

λ = wavelength = 1.09x10^-7 m

R = Rydberg constant = 1.097x10⁷ m^-1

Z = atomic # = 2

n_f = final energy level = ?

n_i = initial energy level = 2

Solve for n_f