Schrödinger & Heisenberg Model

2 Ar 8 8 18 bright line spectrum Recall Bohr’s model of the atom: Bohr’s model of the atom was famous because it could explain the ____________________________________. 2 Ar 8 8 18 bright line spectrum

continuous discontinuous discrete bands The spectrum of white light is _________________, it shows all the colours of the rainbow The spectrum of energized gas is _________________, it shows _________________. discontinuous discrete bands

Each spectrum is a unique “fingerprint.”

E1 Ground state

E1 Ground state 1st excited state

E1 E1 packet of light photon Ground state 1st excited state

E2 Ground state

2nd excited state

E2-E1 E2 E2 1st excited state Ground state 2nd excited state

When particles are exposed to energy ground state (lowest energy state) atoms absorb specific energy and become “excited” an electron moves to a higher shell excited atoms then release the energy at specific frequencies to get back to ground state the electron moves back to its original shell, emitting a photon (packet of light) the difference between two particular energy levels is called the quantum the lines in the spectrum are produced when electrons de-excite

quantum

Bohr’s model was proven significantly wrong in 2 ways: electrons don’t revolve around the nucleus in circles the model can only predict energies in H

Recap What does “ground state” refer to? A. A hydrogen atom B. Lowest energy state of an atom C. Highest energy state of an atom D. When the atom is on the ground

Recap How does an electron become “excited?” A. The atom it resides in reacts with another atom B. It absorbs energy and jumps shells C. It absorbs specific amounts of energy and jumps shells D. When it sees a particle of opposite charge

Recap What is a photon? A. A packet of light B. An excited proton C. An excited electron A Chinese wonton stuffed with Vietnamese noodles

Dalton Thomson Rutherford Bohr Schrödinger

Schrödinger’s model describes the probability of where to find an electron in an atom orbital: the region of space around a nucleus where an electron can be found orbitals are described by quantum numbers

1st or principal quantum number (n) Symbols What does it mean? 1st or principal quantum number (n) 2nd quantum number (l) 3rd quantum number (m) 4th quantum number (ms) 1, 2, 3 … Size and energy level

2s

1st or principal quantum number (n) Symbols What does it mean? 1st or principal quantum number (n) 2nd quantum number (l) 3rd quantum number (m) 4th quantum number (ms) 1, 2, 3 … Size and energy level s, p, d, f Orbital shape

s orbital p orbital d orbital f orbital

1st or principal quantum number (n) Symbols What does it mean? 1st or principal quantum number (n) 2nd quantum number (l) 3rd quantum number (m) 4th quantum number (ms) 1, 2, 3 … Size and energy level s, p, d, f Orbital shape x, y, z Orbital orientation

1st or principal quantum number (n) Symbols What does it mean? 1st or principal quantum number (n) 2nd quantum number (l) 3rd quantum number (m) 4th quantum number (ms) 1, 2, 3 … Size and energy level s, p, d, f Orbital shape x, y, z Orbital orientation ½ or -½ Electron spin

# of Orbitals in a Subshell Maximum # of Electrons in Subshell Each energy level has a specific set of orbitals and each one represents where a maximum of 2 electrons can be found. Orbital Type Begins at n= # of Orbitals in a Subshell Maximum # of Electrons in Subshell   s 1 1 2 p 2 3 6 d 3 5 10 f 4 7 14

Recap What is an orbital? A. The path an electron takes around the nucleus B. Lobes C. The shape of the nucleus D. Mathematical description (probability) of where to find an electron in an atom

Let’s zoom in to each of the Bohr shells Let’s zoom in to each of the Bohr shells. What’s really going on at each shell?

Energy Level Diagram Shell 4 3 orbitals 2 subshells 1

electron-electron repulsion Rules to follow when filling orbitals: Fill orbitals from lowest to highest energy (Aufbau Principle) Place one electron in each orbital of a sub-shell When each orbital of a sub-shell has one electron, go back and pair the electrons (Hund’s Rule) If two electrons are in a orbital, they must have opposite spin (Pauli Exclusion Principle) These rules ensure that the electron configuration gives the ___________ energy, most __________ atom by reducing ________________________________. lowest stable electron-electron repulsion

More About Shells Shell 4 3 2 1 1s22s22p63s23p64s23d104p6 2 8 8 18

How can you write the electron configuration without the energy level diagram???

1s 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 5d 6p 6d 7s 4f 5f

Ar: 1s2 2s2 2p6 3s2 3p6 3p5 3p3 3p1 3p2 3p4

Ga: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1

Ag: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d9

Rn: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6

1s2 2s2 2p6 3s2 3p6 K [Ar] 4s1 1s2 2s2 2p6 3s2 3p6 [Ar] Ti 4s2 3d2 1s2 2s2 2p6 3s2 3p6 Ni [Ar] 4s2 3d8 1s2 2s2 2p6 3s2 3p6 [Ar] Ga 4s2 3d10 4p1 1s2 2s2 2p6 3s2 3p6 Kr [Ar] 4s2 3d10 4p6 Ar

[Ar] 4s2 3d 5

Example: Write the electron configuration for Ga using core notation. Closest previous noble gas element: ______ Core notation:___________________ Ar [Ar] 4s23d104p1

Practice: Write the electron configuration for the following elements. Zn _______________________________ K ________________________________ Kr _______________________________ [Ar]4s23d10 [Ar]4s1 [Ar]4s23d104p6