In Activity 5 (Spectroscoy and Atomic Energy Levels), you learned that light is
ID: 476511 • Letter: I
Question
In Activity 5 (Spectroscoy and Atomic Energy Levels), you learned that light is emitted when excited electrons move from high energy levels to lower energy levels. For each electron transition to a lower level, a photon of light is emitted. We can also cause the opposite phenomenon to occur by aiming high-energy photons (radiant energy) at a material. If the photons are high enough in energy, electrons are promoted to such high energies that they are ionized - they come off the atom completely. This phenomenon is called the photoelectric effect, and is shown in the figure below. This technique is used in photocells and other electronic devices. Photoelectron spectroscopy uses the photoelectric effect to measure the energies of electrons in atoms. Photons of high energies (x-rays or gamma rays) are aimed (incident) at a substance, electrons are ejected and the kinetic energies of the resulting electrons are measured. Energy must be conserved, therefore the binding energy of an electron (E_binding) is equal to the energy of the incident photon (E_Photon) minus the kinetic energy of the ejected electron (E_kinetic): E_binding = E_Photon - E_kinetic If you haven't already done so, you will be learning about ionization energies in lecture. Binding energy is similar to ionization energy, but they are not exactly the same. Ionization energy is commonly used to describe the energy required for the removal of a valence electron, whereas binding energy corresponds to the removal of any electron (often core electrons) from a neutral atom. A photoelectron spectrum shows peaks that each correspond to the energy required to remove each electron. Consider the removal of a 2p and a 3p electron from an argon atom. Which do you think would require the greatest amount of energy? Considering the structure of the atom that you learned in Chapter 2, describe the force that attracts electrons towards the center of an atom and is the reason that energy is required to remove an electron from an atom.Explanation / Answer
part A) 2p orbital electron removal needs more energy than 3p orbital .
part B)
electron has negative charge and proton has positive charge there is electronstatic attraction forces present between two charges. becuase of this electrostatic forces the electron strongly held be nucleous .
in order to remove an electron from any atom we need to supply more amount of energy than this electrostatic forces . the supplied energy is called ionisation energy.