# physics

posted by
**chanty**
.

For a helium atom containing two protons, two neutrons and two electrons:

A)Calculate the first energy levels(n=1,2,3,4,5)(answers (-54.4eV, -6.04eV, -3.4eV, -2.176eV)

b)Calculate the frequency in Hz of a proton emitted from n=2 to n=1 (answer 9.86x 10^15Hz)

c)calculate the wavelength in meters of this emitted photon (answer 3 x 10^-8 m)