$13.$ Order the $3$ types of intermolecular forces and the electrostatic force found in ionic compounds

$($dipole$-$dipole, dispersion, hydrogen bonding, ionic attraction$)$ from weakest to strongest.

WEAKEST

$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

STRONGEST

$14.$ A semiconductor is composed of a silicon crystal that has been $$doped$$ with impurities to make

either an n$-$type $($negative$)$ or p$-$type $($positive$)$ material.

a$)$ Suggest an element that could be used to make each of these types of material. Hint: consider

the Lewis structure of silicon and of the elements you select for doping.

b$)$ Light emitting diodes $($LEDs$)$ make use of semiconductors. When an LED is connected to

a power source, electrons begin to "jump" from the n$-$type material into the p$-$type material.

Using two energy diagrams, show how the electron$$s energy changes when it jumps the gap

between materials in the LED. $($You only need to include $1$ orbital and $1$ electron per diagram$).$

c$)$ According to quantum mechanics, an electron moving from a higher energy state to a lower

energy state will emit a photon at a specific wavelength. The photon$$s wavelength depends on

the change in energy $(\backslash$Delta E$).$

What does this imply about the colour of light emitted by an LED, as compared to a traditional

incandescent light bulb?