Energy of a photon : E = hf The photoelectric effect works like this. If you shine light of high enough energy on to a metal, electrons will be emitted from the metal. Light below a certain threshold frequency, no matter how intense, will not cause any electrons to be emitted.
The Boogie Board Jot 8.5 is an uber-slim slate with a black 8.5â³ screen. The stylus clicks into the opening under the screen. When you use the stylus it writes on the screen in a bright green color. The company claims this board is 50% brighter than their previous Jot model.
With the Boogie Board 8.5 LCD Writing Tablet users of all ages will truly say goodbye to paper forever and it's just as easy to use! Simply press on the surface with the included stylus or other suitable writing instrument (even your finger) to create an image and then erase with the push of a button.