Pre-AP: Flame Test Lab Formal Write-Up requirements Pre-AP: Flame Test Lab Formal Write-Up requirements Name, Partner’s Name, Date performed Name, Partner’s Name, Date performed Title- (specific to lab) Title- (specific to lab) Introduction- (at minimum…ONE paragraph that equals at least FIVE typed lines). Introduces the reader to the lab Introduction- (at minimum…ONE paragraph that equals at least FIVE typed lines). Introduces the reader to the lab Hypothesis- (If, then statement). One sentence that covers the entire lab. Hypothesis- (If, then statement). One sentence that covers the entire lab. Materials- List the ones you used (including the salts) Materials- List the ones you used (including the salts) Procedures-Step by step procedures (may not be able to copy ones from lab exactly. You will probably need to change some steps to follow what you actually did Procedures-Step by step procedures (may not be able to copy ones from lab exactly. You will probably need to change some steps to follow what you actually did Observations-(at least one paragraph, five lines long) Observations-(at least one paragraph, five lines long) Data table-Insert the one you filled out during lab Data table-Insert the one you filled out during lab Analysis-Write the questions you were GIVEN from the lab. Answer the questions thoroughly. You will be given more later to include calculations. Analysis-Write the questions you were GIVEN from the lab. Answer the questions thoroughly. You will be given more later to include calculations. Conclusion-What were your sources of error and how could you fix it for next time to reduce error? Was your hypothesis supported or refuted? Explain. Conclusion-What were your sources of error and how could you fix it for next time to reduce error? Was your hypothesis supported or refuted? Explain.

Chapter 5- Electrons in Atoms 5.1-Light and Quantized Energy 5.2-QuantumTheory and the Atom 5.3- Electron Configuration

5.1-The Development of a New Atomic Model Pages

Waves Wavelength ( ) - length of one complete wave Wavelength ( ) - length of one complete wave Frequency (f) - # of waves that pass a point during a certain time period Frequency (f) - # of waves that pass a point during a certain time period –hertz (Hz) = 1/s Amplitude (A) - distance from the origin to the trough or crest Amplitude (A) - distance from the origin to the trough or crest

Waves A greater amplitude (intensity) greater frequency (color) crest origin trough A

EM Spectrum LOWENERGYLOWENERGY HIGHENERGYHIGHENERGY

LOWENERGYLOWENERGY HIGHENERGYHIGHENERGY ROYG.BIV redorangeyellowgreenblueindigoviolet

Wavelength & Frequency Frequency & wavelength are inversely proportional Frequency & wavelength are inversely proportional c = f c:speed of light (3.00  10 8 m/s) :wavelength (m, nm, etc.) :frequency (Hz, s -1 )

Wavelength & Frequency Example GIVEN: 3.90 X 10 4 Hz = 3.90 X 10 4 Hz =? c = 3.00  10 8 m/s EX:What is the wavelength of a photon whose frequency is 3.90 X 10 4 Hz EX:What is the wavelength of a photon whose frequency is 3.90 X 10 4 Hz = c

Wavelength & Frequency Example GIVEN: = ? = 434 nm = 4.34  m c = 3.00  10 8 m/s WORK : = c = 3.00  10 8 m/s 4.34  m = 6.91  s -1 EX: EX:

Wavelength & Frequency Example GIVEN: = ? = 434 nm = 4.34  m c = 3.00  10 8 m/s WORK : = c = 3.00  10 8 m/s 4.34  m = 6.91  s -1 EX: Find the frequency of a photon with a wavelength of 434 nm. EX: Find the frequency of a photon with a wavelength of 434 nm.

Particle Description of Light Light exhibits some behaviors that are particle-like Light exhibits some behaviors that are particle-like –Photoelectric effect Particles of light are called photons, and they carry a quantum of energy Particles of light are called photons, and they carry a quantum of energy

Energy & Frequency Energy & wavelength are directly proportional Energy & wavelength are directly proportional E = h E:energy (Joules, J) h:Planck’s constant, 6.63x Js :frequency (Hz)

Energy & Frequency Example GIVEN: E = ? v = 3.55x10 17 Hz = 3.55x10 17 s -1 h = 6.63x Js WORK : E=hν E=2.35  J EX: Determine the energy in joules of a photon whose frequency is 3.55x10 17 Hz. EX: Determine the energy in joules of a photon whose frequency is 3.55x10 17 Hz.

Energy & Frequency Example GIVEN: E = ? = 4.57  Hz h = 6.63  J·s WORK : E = h E = ( 6.63  J·s ) ( 4.57  Hz ) E = 3.03  J EX: Find the energy of a red photon with a frequency of 4.57  Hz. EX: Find the energy of a red photon with a frequency of 4.57  Hz.

Some vocab… Ground state-lowest energy state of an atom Ground state-lowest energy state of an atom Excited state-a state in which an atom has a higher potential energy that it has in its ground state Excited state-a state in which an atom has a higher potential energy that it has in its ground state So, how do atoms transition between their ground state and their excited state??? So, how do atoms transition between their ground state and their excited state???

Bohr Model e - exist only in orbits with specific amounts of energy called energy levels e - exist only in orbits with specific amounts of energy called energy levels Therefore… Therefore… –e - can only gain or lose certain amounts of energy because they can exist only at certain energy levels –only certain photons are produced (because only certain amounts of energy is released)

Line-Emission Spectrum ground state excited state ENERGY IN PHOTON OUT Emission spectrum of H 2 gas

Line Emission Spectra Classical theory-atoms would be excited by any amount of energy added to them, and should give off a continuous spectrum of EM radiation. Classical theory-atoms would be excited by any amount of energy added to them, and should give off a continuous spectrum of EM radiation. Attempts to explain further developed the quantum theory of the atom, and led to the Bohr model of the hydrogen atom Attempts to explain further developed the quantum theory of the atom, and led to the Bohr model of the hydrogen atom

Bohr Model Energy of photon depends on the difference in energy levels Energy of photon depends on the difference in energy levels Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom

Other Elements Each element has a unique bright-line emission spectrum. Each element has a unique bright-line emission spectrum. –“Atomic Fingerprint” Helium zBohr’s calculations only worked for hydrogen! 

5.3 Electron Configuration

Where are electrons Found??? Radial Distribution Curve Orbital AKA “electron cloud” AKA “electron cloud” Region in space where there is 90% probability of finding an e - Region in space where there is 90% probability of finding an e -

Atoms are three dimensional… Not “flat” like Bohr’s model with electrons circling the nucleus like the planets circle the sun Not “flat” like Bohr’s model with electrons circling the nucleus like the planets circle the sun 2s 2p z 2p y 2p x

Electron Configuration UPPER LEVEL –Specifies the “address” of each electron in an atom

General Rules Pauli Exclusion Principle Pauli Exclusion Principle –Each orbital can hold TWO electrons with opposite spins.

General Rules Aufbau Principle Aufbau Principle –Electrons fill the lowest energy orbitals first. –“Lazy Tenant Rule”

RIGHT WRONG General Rules Hund’s Rule Hund’s Rule –Within a sublevel, place one e - per orbital before pairing them. –“Empty Bus Seat Rule”

Representing e - configurations 3 ways to represent e - configurations 3 ways to represent e - configurations –Orbital notation –Electron configuration notation –Noble gas notation

Orbital notation Orbitals are represented by lines or boxes that are labeled with the energy level and sublevel Orbitals are represented by lines or boxes that are labeled with the energy level and sublevel e - are represented as arrows e - are represented as arrows – ↑ =+ ½ e - spin – ↓ =- ½ e - spin O 8e - 1s 2s2p **Remember Hund’s Rule!!**

© 1998 by Harcourt Brace & Company s p d (n-1) f (n-2) Periodic Patterns

Orbital notation practice Draw the orbital notation for Draw the orbital notation for –He –Li –Na –Si –Ne –Ca

e - Configuration Notation Energy levels and sublevels are represented by numbers and letters Energy levels and sublevels are represented by numbers and letters Electrons are represented by superscripted numbers Electrons are represented by superscripted numbers O 8e - 2p 2s 1s 2 2 4

e - Configuration Notation practice Write the e- configuration notation for the following elements: Write the e- configuration notation for the following elements: –Be –Ge –S –Cd

Some vocab… Valence electrons-electrons that are found in the highest occupied energy level Valence electrons-electrons that are found in the highest occupied energy level –Highest occupied energy level-electron- containing main energy level with the highest principal quantum number Inner shell or core electrons-electrons that are not in the highest occupied energy level Inner shell or core electrons-electrons that are not in the highest occupied energy level

Noble Gas Notation “Abbreviated” form of e- configuration notation “Abbreviated” form of e- configuration notation Use the noble gas (Gp. 18) that immediately precedes the element of interest as shorthand for the majority of the notation Use the noble gas (Gp. 18) that immediately precedes the element of interest as shorthand for the majority of the notation Write the e- configuration notation for Ne and compare it to S. What do you notice? Write the e- configuration notation for Ne and compare it to S. What do you notice?

Noble Gas Notation Only difference is the valence electrons in sulfur. Use [Ne] as an abbreviation for all parts that are the same! Only difference is the valence electrons in sulfur. Use [Ne] as an abbreviation for all parts that are the same! S 16e - 1s 2 2s 2 2p 6 3s 2 3p 4 Ne 10e - 1s 2 2s 2 2p 6 S16e - [Ne] 3s 2 3p 4

Noble Gas Notation practice Write the noble gas notation for the following elements: Write the noble gas notation for the following elements: –Cl –B –Sr –I

Periodic Patterns Period # Period # –energy level (subtract for d & f) A/B Group # A/B Group # –total # of valence e - Column within sublevel block Column within sublevel block –# of e - in sublevel

s-block1st Period 1s 1 1st column of s-block Periodic Patterns Example - Hydrogen Example - Hydrogen

Periodic Patterns Noble Gas Notation Noble Gas Notation –Core e - : Go up one row and over to the Noble Gas. –Valence e - : On the next row, fill in the # of e - in each sublevel.

[Ar]4s 2 3d 10 4p 2 Periodic Patterns Example - Germanium Example - Germanium

Full energy level Full energy level Full sublevel (s, p, d, f) Full sublevel (s, p, d, f) Half-full sublevel Half-full sublevel Stability

–Copper EXPECT :[Ar] 4s 2 3d 9 ACTUALLY :[Ar] 4s 1 3d 10 –Copper gains stability with a full d-sublevel. Exceptions

–Chromium EXPECT :[Ar] 4s 2 3d 4 ACTUALLY :[Ar] 4s 1 3d 5 –Chromium gains stability with a half-full d- sublevel. Exceptions

Configuration of Ions Ion Formation Ion Formation –Atoms gain or lose electrons to become more stable. –Isoelectronic with the Noble Gases.

O 2- 10e - [He] 2s 2 2p 6 Configuration of Ions Writing Ion Electron Configuration Writing Ion Electron Configuration –Write the e - config for the closest Noble Gas –EX: Oxygen ion  O 2-  Ne