Electrons What causes what you are seeing

Electrons What causes what you are seeing?

Sample Flame color Flame description

Electron Configuration Mapping the electrons

Electron Configuration n The way electrons are arranged around the nucleus.

Quantum Mechanical Model n n 1920’s Werner Heisenberg (Uncertainty Principle) Louis de Broglie (electron has wave properties) Erwin Schrodinger (mathematical equations using probability, quantum numbers)

Heisenberg uncertainty principle n it is impossible to determine simultaneously both the position and velocity of an electron or any other particle with any great degree of accuracy or certainty.

Erwin Schrodinger Ø Ø Ø Formulated equation that describes behavior and energies of subatomic particles. Incorporates both particle and wave behavior in terms of wave function: is proportional to the probability of finding an electron. Leads to Quantum Mechanics: we cannot pinpoint an electron in an atom but we can define the region where electrons can be in a particular time……… called a Probability map…. a 3 -dimensional area in space called an ORBITAL

Like building a house…. . n Orbitals are like a house. There are floors, rooms, closets and balconies. n Keep that in mind…… n

Principal Quantum Number, n n Indicates main energy levels n = 1, 2, 3, 4… This is like how many floors your house has n n Each main energy level has sub-levels This is like what kind of rooms are on each floor

Energy Sublevels s p d f

n The principle quantum number, n, determines the number of sublevels within the principle energy level. Basically each floor can only have certain types of rooms-answer questions….

Orbital Quantum Number, ℓ (Angular Momentum Quantum Number) n n Indicates shape of orbital sublevels ℓ = n-1 ℓ sublevel 0 1 2 3 4 s p d f g

Orbital n n The space where there is a high probability that it is occupied by a pair of electrons. How many in a pair? Orbitals are solutions of Schrodinger’s equations.

Orbitals

Visualizing the orbitals n n Back to the house…… Orbitals are the rooms that hold 2 people per room.

Orbitals in Sublevels Sublevel # Orbitals s 1 p 3 d 5 f 7 # electrons 2 6 10 14

Three rules are used to build the electron configuration: Aufbau principle n Pauli Exclusion Principle n Hund’s Rule n

Aufbau Principle Electrons occupy orbitals of lower energy first. n Like building a house- lower floors fill up first n

Orbital Diagram

Filling Order diagram

-Pauli Exclusion Principle (Wolfgang Pauli, Austria, 1900 -1958) -Electron Spin Quantum Number n An orbital can hold only two electrons and they must have opposite spin. Electron Spin Quantum Number (ms): +1/2, -1/2 Imagine people in a house on feet…… n

Hund’s Rule In a set of orbitals, the electrons will fill the orbitals in a way that would give the maximum number of parallel spins (maximum number of unpaired electrons). Analogy: Students could fill each seat of a school bus, one person at a time, before doubling up.

Orbital Diagram for Hydrogen

Orbital Diagram for Helium

Orbital Diagram for Lithium

Orbital Diagram for Beryllium

Orbital Diagram for Boron

Orbital Diagram for Carbon

Orbital Diagram for Nitrogen

Rappers Resort

Orbital Diagram

Orbital Diagram for Fluorine

Notations of Electron Configurations n n Standard Shorthand

Standard Notation – electron configurations n n n If I had to send mail to someone living in the house you just built how would I address the envelope? I would have to do the following. Floors I have to climb to get to you Type of rooms I pass How many people are living in the rooms

Match up n Who is who in this situation? Floors I have to climb electrons Type of rooms I pass Principle energy levels How many people are living orbitals in the rooms

ALWAYS!!! ROW BLOCK # OF BLOCKS

Color it in!

What do you notice about the d block? n n the d block _______ so instead of 4 d it is _____. Why? It’s like closets in bedrooms.

Standard Notation of Fluorine 2 1 s rgy ne in E Ma el ev bers L um 2 N , , 2 1 Number of electrons in the sub level 2, 2, 5 2 2 s 5 2 p Sublevels

Practice n He Li n P n O n Fe n

Shorthand Notation- Noble gas configurations n n Use the last noble gas that is located in the periodic table right before the element. Write the symbol of the noble gas in brackets. Write the remaining configuration after the brackets. Ex: Fluorine: [He] 2 s 2 2 p 5

Practice n n Ca Al Br Cu

Lewis Dot Structures n Models to show many valence electrons are in the A group elements. This doesn’t apply to group B n Group # = Dots! n

Examples

You try! n Xe n Cs n Sr n I

Electrons get excited! n n Electrons can gain energy and move to an excited state and emit energy in specific wavelengths of light we can see! How?

Ground state n n Electrons have a ground state – or a state in which they normally exist. When energy is added to the system they jump to the next level ON the RETURN to ground level they emit light in our visible spectrum.

Visible spectrum

Flame test. n n We are going to solve a crime……. See flame test worksheets

That’s it n Good luck on your test!