Chapter 5, Problem 5.132MP

The amount of energy necessary to remove an electron from an atom is a quantity called the ionization energy, $E_i$ . This energy can be measured by a technique called photo electr on spectroscopy, in which light of wavelength $\lambda$ is directed at an atom, causing an electron to be elected. The kinetic energy of the ejected electron $\left(E_k\right)$ is measured by determining its velocity, $v\left(E_k=m{v}^2\text{/2}\right)$ , and $E_i$ is then calculated using the conservation of energy principle. That is, the energy of the incident light equals $E_i$ plus $E_k$ . That is the ionization energy of selenium atoms in kilojoules r mole if light with $\lambda =48.2\text{nm}$ produces electrons with a velocity of $2.371\times {10}^6\text{m/s}$ ? The mass, m, of an electron is $9.109\times {10}^{-31}\text{kg}$ .