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.
The Parker Jotter is the Parker Pen Company 's second and best-selling retracting refillable ballpoint pen. The first was the Hopalong Cassidy ballpoint. (Later a fountain pen, mechanical pencil and roller ball pen were introduced to the line. In 2004, the Jotter's Jubilee, the company released a number of special editions. 2  The flat button was restored to its original rounded shape that it had prior to 1973 and was imprinted with the number '50' signifying the pen's fiftieth anniversary of production.