7.4 the Bohr model (hydrogen atoms)

Question 1

what happens when electrons go from high to low energy levels

Answer 1

emit (environment gains energy ) excess energy in the form of photon (light) +

Question 2

what happens when electrons go from low to high energy levels

Answer 2

must be excited, receive (environment loses) energy ( photon) -

Question 3

what is the equation to calculate the change in energy of an electron

Answer 3

ΔE = -2.178^-18 J (Z“2/n“2)

ΔE = -2.178^-18 J (1/n final “2 - 1/n initial“2 )

when ΔE has been found, we can find wavelenght photon by using

λ= hc/ΔE

Question 4

why is there a - sign in the equation?

Answer 4

means that the energy of the electron bound to the nucleus is lower than it would be if the electron was at an infinite distance (n = infinity) from the nucleous. (closer you are to the nucleous, the more you are bound to it)

Question 5

what is the sign convention

Answer 5

when goes from high to low, emits energy, so +
when goes from low to high, needs energy, so -

Question 6

what does it mean when delta E is posotive or negative

Answer 6

positive = absorbed (the photon absorbed energy)
negative= emitted (the photon gave energy)