6. Which of the following are valid wavefunctions, in that they satisfy the required boundary conditions? If it is a valid wavefunction, sketch the approximate probability distribution, and also state how many energy states there are with energies lower than this one. Note that the potential energy goes to infinity at x=0 and x=2 nm. 12 1.8 10 1.6 00 1.4 1.2 Energy (ev) Energy (ev) N D 0.2 0 O 0 0.5 1 1.5 2 0.5 1 1.5 2 x (nm) x (nm) 3 1.8 2.5 N 1.5 Energy (ev) Energy (ev) 0.5 0 O 0.5 1 1.5 2 0 0.5 1 1.5 2 x (nm) x (nm)