Quantum Model of the Atom

Do Now What do we know about the atom based on Bohr’s model?

Bohr’s Model Central nucleus Electrons revolved in circular orbits However, only worked for hydrogen

The Quantum Model 1926- proposed by Schrödinger Treated the electron like a wave Heisenberg’s Uncertainty Principle it is impossible to know the velocity and position of a particle at the same time Therefore it is nearly impossible to know the exact location of an electron at any exact moment.

Like Bohr’s model, there are different energy levels As electrons travel away from the nucleus, they require more energy Like climbing a ladder The high your climb, the more energy you use

Orbital Shapes Inside each energy level there are different shaped orbitals s p d f (in order of increasing energy)

First Energy Level 1 sublevel s-shaped orbitals Has one sub-orbital Holds 2 electrons

Second Energy Level 2 sublevels s-shaped p shaped 1 sub-orbital Holds 2 electrons p shaped 3 sub-orbitals Holds total of 6 electrons (2 per sub-orbital)

Third Energy Level 3 sublevels s-shaped p-shaped d-shaped 1 sub-orbital Holds 2 electron p-shaped 3 sub-orbitals Holds 6 electrons d-shaped 5 sub-orbitals Holds 10 electrons (2 per sub-orbital)

Fourth Energy Level 4 sublevels s-shaped p-shaped d-shaped f-shaped 1 sub-orbital Holds 2 electrons p-shaped 3 sub-orbitals Holds 6 electrons d-shaped 5 sub-orbitals Holds 10 electrons f-shaped 7 sub-orbitals Holds 14 electrons

Each energy level acquires a sublevel Each sublevel is a different shaped orbital

Aufbau’s Principle Electrons will occupy the lowest available energy level first Energy levels closest to the nucleus have less energy Like climbing a ladder

Pauli’s Exclusion Principle Hund’s Rule Electrons will occupy each sub-orbital before pairing up School bus Pauli’s Exclusion Principle When electrons are paired together, they will spin in opposite directions