Clicker #1 How many of the following statements are true concerning an electron in its ground state? I.The electron must be in its lowest-energy state. II.Energy must be applied to the electron in order to excite it. III.The electron must be located on the nucleus of an atom. IV.The electron can release energy to obtain a lower ground state. A)0 B) 1C) 2 D) 3E) 4

“Waves” and “Particles” An electron can behave like a particle An electron can behaves like a wave (every electron has a wavelength associated with it) Louis Victor de Broglie and Erwin Schrödinger

Wave Properties (Slinky) Can cancel and add up The more energy they have the more complicated the wave gets Waves are associated with probability If a wave cancels (i.e.- wavelength = 0) then there is zero probability you will find an electron there

Wave Properties (Slinky) Can cancel and add up The more energy they have the more complicated the wave gets Waves are associated with probability If a wave cancels (i.e.- wavelength = 0) then there is zero probability you will find an electron there QUANTIZED ENERGY!!!!!!!!

Think of electrons in terms of probabilities! Firefly example

Electron wants to be near nucleus Electron cannot be in certain regions (i.e.- 0 probability) Electron can only have certain energy levels

Electron Electrons are most probable to be found near the nucleus Electrons could be anywhere We can’t tell how the electrons move Regions of probability = ORBITALS!

ORBITALS Size and Complexity

Orbital Rules Each energy level is one more kind of orbital Odd number of orbitals for each kind (1, 3, 5, 7, etc…) Specific number of electrons can fit into each orbital Electrons go to the lowest energy state FIRST (closer to the nucleus)

Clicker #2 How many electrons can fit in a set of d orbitals in the third energy level? How many electrons can fit in a set of f orbitals in the fourth energy level? A)1; 1 B)2; 2 C)5; 7 D)10; 14 E)15; 28

Clicker #3 Why is diagram #1 preferred over diagram #2? diagram #1 diagram #2 A)Because spreading out between orbitals of equal energy will minimize electron-electron repulsions. B)Because each orbital “wants” an electron and this way two of the orbitals will be “happy”. C)Because this way there are fewer electrons in the element so the nucleus can have a greater positively charged pull overall. D)Because this arrangement allows us to better predict the wavelength (and thus color) of light that will be emitted to return to its ground state.

Rules for filling orbitals Two electrons can fit into each orbital Electrons go to the lowest energy state FIRST (closer to the nucleus) Doesn’t matter which orbital you fil first within the same energy level Electrons don’t want to pair up until they have to (charges repel)