What is the kinetic energy and speed of an electron ejected from a sodium surface whose work function is W = 2.28 eV when illuminated by light of wavelength a) 410 nm and b) 550 nm.

a) 1.25×10^-19J

b) 0J

Explanation:

We must first obtain the energy of the photons using their respective wavelengths given as shown in the solution attached. Then we convert the work function of the metal from electron volts to joules as shown. Then we apply Einstein's photoelectric equation as shown. This gives us the kinetic energy of the emitted photoelectron in each case. In the second wavelength does not have sufficient energy to impart kinetic energy to the emitted photo electrons.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.