Electrons in Atoms: Electron Configuration Chemistry EQs: What is the relationship between matter...
-
Upload
brianna-potter -
Category
Documents
-
view
220 -
download
1
Transcript of Electrons in Atoms: Electron Configuration Chemistry EQs: What is the relationship between matter...
Electrons in Atoms: Electrons in Atoms: Electron ConfigurationElectron Configuration
Chemistry EQs: What is the relationship between
matter and energy?How does the behavior of electrons affect
the chemistry of atoms?
GPSGPS
SC3 Students will use the modern atomic theory to explain the characteristics of atoms.b. Use the orbital configuration of neutral atoms to explain its effect on the atom’s chemical properties.f. Relate light emission and the movement of electrons to element identification.
VocabularyVocabulary
Aufbau PrinciplePauli Exclusion PrincipleHund’s RuleElectron ConfigurationValance ElectronEnergy levels
Lewis StructureGround stateExcited stateOrbitalsQuantum
Excited ElectronsExcited Electrons
Bohr Model of the Atom:Bohr Model of the Atom:
Bohr’s Model: electrons orbit the nucleus; only orbits in certain energies are permitted.
Ground State- lowest E levelExcited State- Higher than ground state.
◦The e- are raised to the next level, then release light when they return to ground state
Must have enough E to raise to next level or won’t happen.
Bohr ModelBohr Model
Bohr Model of the atomBohr Model of the atom
ElectronsElectrons
DeBroglie- Quantum Mechanics- light behaves
as wave & particles Visible objects (baseball) have too
small to see, need very small object to detect
Heisenburg Uncertainty Principle- Can’t know the position & speed of electron at the same time
Bohr Model Bohr Model Quantum Model Quantum ModelE- do not fall towards nucleus E- reside in electron clouds called orbitals
ElectronsElectrons
Energy levels- region around nucleus where e- likely to be found (electron density is high)
Quantum- amount of energy for e- to jump levels
Continuous- ramp, no units Quantitized- fixed levels, fixed units
Schrodinger- estimates the probability of e- to be in certain area; electrons are like a fuzzy cloud, but more dense= more likely to find e- 90% of the time in a particular location
Orbitals-Wave functions with corresponding densities (shape and energy)
**orbital is NOT the same as Bohr’s orbit
Electron configurationElectron configurationRow=Period=Energy Level => horizontalColumn= Group/ Family=> vertical
◦ Elements in the same family have the same # of valence electrons & share similar chemical properties.
Valence electrons= e- in to last energy level.◦Valence e- correspond w/ group # (does not
include transition elements): Group 1A= 1 valence e- Group 2A= 2 valence e- Group 3A (13) = 3 valence e- Group 4A (14) = 4 valence e- Group 5A (15) = 5 valence e- Group 6A (16) = 6 valence e- Group 7A (17) = 7 valence e- Group 8A (18) = 8 valence e- FULL SET; STABLE
Electron ConfigurationElectron Configuration Tells the arrangement of electrons around
the nucleus of an atom Written in ground state, which is the lowest
energy & most stable arrangement e- arrange from lowest to highest E level
Electron configurationElectron configuration..
Orbital: the 3-D space around the nucleus that describes an electrons probable location.
Energy Level (n): indicate the relative sizes & energies of atomic orbitals. ◦ As n increases, the orbitals become larger, and the e-
spends more time farther from the nucleus. ◦ n = major energy levels; n = 1-7; correspond w/ the 7
rows on the P.T. Sublevel: energy levels contained w/in a energy
level; s, p, d, f
Electron ConfigurationElectron Configuration
What shape are the orbitals?What shape are the orbitals?
s and p Orbitals
Electron ConfigurationElectron Configuration Tells the arrangement of electrons around
the nucleus of an atom
Written in ground state, which is the lowest energy & most stable arrangement
Follows 3 rules:1. Aufbau Principle2. Pauli Exclusion Principle3. Hund’s Rule
Aufbau PrincipleAufbau Principle
Each electron will occupy the lowest available energy level 1st, then higher energy levels.
Pauli Exclusion PrinciplePauli Exclusion Principle A maximum of 2 electrons with opposite
spins can fit in an orbital (No more than 2 e- can
occupy orbitals). e- in the same orbital must have opposite
spin (repulsion); ◦ Show each orbital w/ its own box◦ One is spinning clockwise & the other is counter
clockwise, Show this with one arrow going up & one pointing down.
NOT
Hund’s RuleHund’s RuleSingle electrons with the same spin must
occupy each equal energy level before additional electrons with opposite spins can be added
e- enter orbitals singularly, then pair up◦Example: when filling the p sublevel with 4e-,
each box gets 1 before doubling up one box
NOT
Using the PT:•The principal quantum number , n = period.•There are 4 blocks: (s, p, d, f)•Noble gases:full s & p level making them inert (stable).•Alkali Metals- s1
•Alkaline Earth Metals- s2
•Transition Elements- d1-d10
•Inner Transition Elements- f1-f14
Electron ConfigurationElectron Configuration--
Electron Fill SequenceElectron Fill Sequence
Electron ConfigurationElectron Configuration
Electron Sequence ModelElectron Sequence Model
1s
2s
3s
4s
5s
6s
7p
6p
5p
4p
3p
2p
6d
5d
4d
3d
4f
5f
7s
Follow the yellow brick road
Electron ConfigurationElectron Configuration
Examples:F 1s22s22p5
Cl 1s22s22p63s23p5
Al 1s22s22p63s23p1
Br 1s22s22p63s23p64s23d104p5
Orbital Diagrams”Orbital Diagrams”Uses boxes to represent orbitalsUses boxes to represent orbitals
1s 2s 2p 3s 3p 4s 3d 4p
1s 2s 2p 3s 3p 4s 3d 4p
1s 2s 2p 3s 3p 4s 3d 4p
1s 2s 2p 3s 3p 4s 3d 4p
Noble Gas NotationNoble Gas NotationSimplified version of writing e- configurationsNoble gas is placed in brackets [ ]
Noble Gas ShortcutNoble Gas Shortcut
When doing configurations for large numbers of electrons, we can take a short cut using noble gases. (yay!)
Example, lets try Sulfur: (16 electrons)◦The noble gas that comes before Sulfur is: Neon◦Noble gas is placed in brackets [ ]◦Place noble gas in bracket to represent the e-
configuration up to that noble gas.◦Write the rest of the e- config. for that element.◦So we could shortcut by writing: [Ne] 3s2 3p4
Now you try: Manganese and Strontium
Electron Configuration and Orbital Electron Configuration and Orbital NotationNotation
Valence ElectronsValence Electrons
e- in the outer most energy level that determines chemical properties
Lithium = 1s2 2s1
Bromine = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
Aluminum = [Ne] 3s2 3p1
Family NumberVE are the electrons available to form chemical bonds w/ other elements.
Lewis Dot Structure: Electron Lewis Dot Structure: Electron DotDotChemical symbol & valence electrons of atom
Valuable in showing how atoms share electrons in covalent bonds
We can draw Lewis structures for every element using valence electrons
Count the # of valence electron, then arrange then around the symbol for the atom one at a time; up to 8 electrons.
Arrange 1/ side around the symbol, then couple up if more than 4 electrons.
Lewis DotLewis Dot