please help me please

Question

A student is studying a mystery element and observes two distinct bands in the element's emission spectrum (shown below). One band appears at a wavelength of 450 nm while the other appears at a wavelength of 650 nm. The student knows that each band that she observes must be due to an electron transition within the atom. She draws the Bohr model shown below to represent the two transitions that are occuring.

Which electron transition (arrow A or B) likely leads to the band at 450 nm? Explain you answer being sure to include which transition involves more energy and how the energy is related to wavelength.

Answer 1

Hello, Aseel,

There is no diagram in the question showing the A and B electron transitions. Generally speaking, the further an electron moves between orbital energy levels, the greater the energy involved. In an emission spectrum, the electron's are moving from high to low energy levels and emitting the energy difference as light energy. The shorter the wavelength, the higher the energy. The 450nm band reflects the higher energy transition, so the line showing the greatest change in energy levels is likely the source of this emission.

Wavelength and frequency are related: c = λ · ƒ where c is the speed of light, lambda is the wavelength and f is the frequency.

Bob