When the complete photoelectron spectrum for an element is shown, what does each peak in the spectrum represent?

• A. Electrons ejected from a specific atomic orbital with a characteristic binding energy
• B. The energy levels of electrons after they have absorbed energy
• C. The total number of protons in the nucleus of the element
• D. The number of photons absorbed by the element at different wavelengths

Answer: (A)

Verified step by step guidance

1. Understand that a photoelectron spectrum is obtained by irradiating an element with photons and measuring the kinetic energy of electrons ejected from the atom.
2. Recognize that each peak in the photoelectron spectrum corresponds to electrons coming from a specific atomic orbital within the atom.
3. Know that the position of each peak is related to the binding energy of electrons in that particular orbital, which is the energy required to remove an electron from that orbital.
4. Recall that the binding energy can be calculated using the equation \(E_{binding} = h\nu - E_{kinetic}\), where \(h\nu\) is the photon energy and \(E_{kinetic}\) is the kinetic energy of the ejected electron.
5. Conclude that each peak represents electrons ejected from a specific atomic orbital with a characteristic binding energy, reflecting the electronic structure of the element.