Chem help!?

1) Rydberg equation for hydrogen electron transitions:

ΔE = - RH * [(1/n²f) - (1/n²i)]

RH = Rydberg constant = 2.180 x 10^-18 J

ni = initial energy level

nf = final energy level

In this case, ni = 4, nf = 2, so

ΔE = (-2.180 x 10^-18 J) x [(1/2²) - (1/4²)]

= - 4.088 x 10^-19 J

That's the ΔE for one photon. The negative sign indicates that radiation was emitted. The question asks for the ΔE in kJ of a mole of photons, so multiply by Avogadro's number and convert J to kJ.

(-4.088 x 10^-19 J / 1 photon) x (6.022 x 10^23 photons / 1 mole) x

(1 kJ / 1000 J)

= -246 kJ/mol . . . . . . to 3 significant figures

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The mass of a golf ball is 45.9 g . If it leaves the tee with a speed of 61.0 m/s , what is its corresponding wavelength?

deBroglie wavelength equation:

λ = (h / mv)

λ = wavelength

m = mass (kg)

h = Planck’s constant = 6.626 x 10^-34 J•s = 6.626 x 10^-34 kg•m²/s

mass = 45.9 g = 0.0459 kg

λ = (6.626 x 10^-34 kg•m²/s) / [(0.0459 kg) x (61.0 m/s)]

= 2.37 x 10^-34 m