**Wavefunction:** Schrodinger’s equation is a way to see the trajectory of light as a wave.

**Probability Density:**

Schrodinger’s equation SQUARED.

The probability that an electron will be found in a small region of volume.

**Node:**

A location where the electron WON’T travel, aka the wavefunction = 0

If an electron is “in-between” two energy levels, then it’s a node cause it is impossible, so the energy level is 0

**Angular Nodes:**

Between lobes

(Just the l-value)

**Radial nodes:**

The nodes between energy levels

(n – l – 1)

**Allowed in One-electron systems like Hydrogen:**

One-electron just means it has one electron, like hydrogen, helium ion, or lithium-ion with 1+ and 2+

Z = Atomic number, so for Hydrogen, it would just be 1

n = Energy level

R = Rydberg’s Constant

h = Planck’s Constant

**Why is energy NEGATIVE:**

Energy is negative because they are compared to the energy of a free electron.

This means how much ENERGY is needed to POP-OFF an electron.