Electron Properties and Arrangement Chapter 5 Objectives: Identify properties of electrons. Understand how electrons move in atoms. Distinguish between atoms based on their different electron arrangements..

Electron Properties: Infinite Campus Update: Atomic Structure and Nuclear Chem Gallery Walk (5pts.) Electron Properties and Arrangement Bell Ringer (4pts.) Objectives: Identify properties of electrons. Understand how electrons move in an atom.

Bohr’s Model of the Atom Electrons travel in fixed, circular paths around the nucleus. Each path has a specific energy requirement. These circular paths are called energy levels. Limited number of electrons on each energy level. (2n 2 Rule)

Electrons and Light Particles Electron Properties: Very tiny particles Extremely small masses Move at very high speeds (3.0x10 8 m/s) Electron movement is identified by the absorption and emission of light particles by electrons.

Current Atomic Model Electrons do not travel in fixed paths around the nucleus *Electrons constantly move to different energy levels in the electron cloud. *Direction of e- movement is dependent upon energy absorbed or released. Erwin Schrodinger

Electron Movement

Atoms Interaction with Light Particles Light Particles Atom Electrons absorb light particles Electrons absorb specific light particles. Electrons that absorb photons can move to higher energy levels.

Electromagnetic Radiation Spectrum Electromagnetic Spectrum : Divides light particles into regions based on their wave-like properties. a. Relationship b/w wavelength and frequency? b.Relationship b/w wavelength and energy emission? c.Relationship b/w frequency and energy emission?

Wave-Like Properties: Wavelength Wavelength: length of wave from two neighboring crest. Amplitude: height of wave from origin to crest.

Wave-Like Properties: Frequency Wave-Like Properties: Frequency Frequency ( Hz ) : how many waves pass a certain point per second. Units: Hertz (Hz.)= (waves/second)

Wave-Like Properties: Energy Temperature : Represents amount of energy emitted from light particles. Photons: Light particles classified by energy emitted. *Electron movement dependent upon type of photons absorbed or released.

Flame Test Lab Purpose: Heat matter (atoms) so that we can observe the emission of photons from electrons.

Electron Movement

Electron Properties: Infinite Campus Update: Atomic Structure and Nuclear Chem Gallery Walk (5pts.) Electron Properties and Arrangement Bell Ringer (4pts.) Objectives: Identify properties of electrons. Understand how electrons move in an atom.

Flame Test Lab Conclusion: What properties of electrons were observed from this lab? Post-Lab Questions:

Color’s Wavelength Each color has its own unique wavelength.

Electromagnetic Spectrum Applications “Electromagnetic Spectrum Song” by Emerson and Wong Yann

Flame Test Lab Post-Lab Questions: 1.What direction were the electrons moving when the flame turned colors? Explain. 2.Was the flame test a helpful method in identifying the unknown solutions? Explain your answer. 3.Which solution emitted the longest wavelength of light? Shortest wavelength of light? 4.What is another example you have observed of chemicals producing beautiful colors when they are burned?

Electromagnetic Spectrum Analysis 1

Wave-Like Properties: Frequency Wave-Like Properties: Frequency Frequency ( Hz ) : how many waves pass a certain point per second. Units: Hertz (Hz.)= (waves/second)

Visible Region of EM Spectrum loke.as.arizona.edu

Doppler Effect

Provides evidence of galaxy movement, Edwin Hubble. Our universe is expanding and at an increasing rate. Validates the Big Bang Theory-how our universe was created.

Fireworks: Emission of Light Example of elements that can give minerals their unique colors. barium= pale green strontium = red copper = blue-green sodium= yellow These are common metals used in fireworks.

Electromagnetic Spectrum Analysis 1

Electron Properties: Infinite Campus Update: Atomic Theory and Nuclear Reaction Exam(44pts.) Electron Probability Packet (23pts.) Due: “ Where Do Elements Come From” packet Objectives: Understand how electrons move in an atom Predict the arrangement of electrons in an atom at ground state.

Current Atomic Model Electrons do not travel in fixed paths around the nucleus *Electrons constantly move to different energy levels in the electron cloud. *Direction of e- movement is dependent upon energy absorbed or released. *Electrons move around the nucleus in different shaped paths. Erwin Schrodinger

Electron Movement 1.Ground state of H Atom (lowest energy level for e-) 2.A photon (light particle) is absorbed by H’s electron. Electron becomes excited and jumps to higher energy level. 3. E- returns to ground state and emits (releases) the photon. Emitted photon’s wavelength can be detected by scientists. (Infrared region at room temp; Visble region at higher temps.)

Electromagnetic Spectrum Analysis 1

Emission Spectrums Each element has a unique emission spectrum. (flame test lab). Scientist can calculate the energy value of each emission band.

Elements in Stars A star is a sphere of super hot gases—mostly hydrogen and helium. How do we know this? Every chemical element has a unique emission spectrum. Emission spectrums help astronomers identify the composition of stars. Hydrogen 69% Helium 29% Heavier elements 2 % Carbon, Oxygen, Nitrogen, & Calcium

Temperature of Stars

Electron Movement in Energy Levels Quantum of energy: Specific energy that is absorbed or emitted by electrons as they move between energy levels. Energy difference between two energy levels. Scientist can calculate energy emitted by electrons. Determine what energy levels electrons move between in an atom.

Locating an Electron Is it possible to know the exact location and velocity of an electron at any instant in time? Very difficult to locate an electron because: - moving extremely fast -continuously bombarded by light particles When locate an electron with a photon from a microscope, it changes its velocity in unpredictable ways.

Photon Before Photon changes wavelength After Heisenberg Uncertainty Principle It is not possible to know the exact position and speed of an electron at the same time.

The Quantum Mechanical Model An atomic model that best explains the probable arrangement and movement of electrons at any moment in time. Schrodinger provided evidence for this model using a complex mathematical equation. Depends upon 4 quantum numbers. Erwin Schrodinger

n-Quantum Number n = energy levels 3-D region of space around the nucleus where an electron can be found. Each energy level has a specific energy value. E- must absorb or release a specific quantum of energy to move between energy levels. E- do not travel in an orbit (exact path) around the nucleus. Atomic orbitals: Probable paths an electron would take around the nucleus.

Associate energy levels with rows on the periodic table.

n-Quantum Number Limited number of electrons on each energy level. 2n 2 Rule determines the maximum number of electrons on each energy level.

l–Quantum Number l -number : Sublevels within an energy level. Sublevels identify the shape of the orbitals. There are four different sublevels: s, p, d, f

Orbital Shapes A maximum of 2 electrons can move in each orbital.

Associate orbitals with certain columns on the periodic table.

Electron Properties: Due: “ Where Do Elements Come From” packet Electron Configuration Worksheet Objectives: Understand how electrons move in an atom. Predict the electron configuration of an element at ground state. Homework: Review notes: Quiz over electromagnetic spectrum and first two quantum numbers.

Bell Ringer: Electron Arrangement 1. What is the name of the atomic model that best explains electron arrangement? 2. a. What is the n-quantum number? b. T or F: Electrons move around the nucleus in an exact path. c. What is the maximum number of electrons that can be on the 6 th energy level at any time? 3. a. What is the l-quantum number? b. Illustrate the s, p, d, f atomic orbitals? c. How many electrons can move in each atomic orbital at any one time?

Electromagnetic Spectrum Analysis

Orbital Shapes A maximum of 2 electrons can move in each orbital.

Orbitals and Energy Requirement Electron movement defines orbital shapes for each sublevel. Electrons need energy to move in orbital shapes. Sublevel’s OrbitalsEnergy for electron movement (Rank in increasing amount of energy) S-orbital P-orbital D-orbital F-orbital

Electron Configuration:

Orbital Shapes A maximum of 2 electrons can move in each orbital.

Electron Properties: Objectives: Electron Movement Quiz Understand how electrons move in an atom. Predict the electron configuration of an element at ground state..

Electron Configuration Electron Configuration Rules: Aufbau Principle: Electrons will move in an orbital of lower energy first. (Electrons are lazy!) Pauli Exclusion Principle: Only two electrons can move in an orbital at the same time. Hund’s Rule: When electrons can move in orbitals of the same energy, they will prefer to be alone before pairing up. (Electrons are selfish!)

Electron Configuration:

m- Quantum Number m –number: Orientations for each atomic orbital. Orbital orientations: The different ways an electron can make an orbital in 3-D space.

S-Orbital Orientation Maximum # of s-orbital electrons on an energy level? How many s-orbitals are possible on an energy level?

P-orbital Orientations Maximum # of p-orbital electrons on an energy level? How many p-orbitals are possible on an energy level?

D-orbital Orientations Maximum # of d-orbital electrons on an energy level? How many d-orbitals are possible on an energy level?

F-orbital Orientations Maximum # of f-orbital electrons on an energy level? How many f-orbitals are possible on an energy level?

Orbital Orientations

Electron Configuration Orbital Notation H: C: Zn:

S-Quantum Numbers S-number : The direction an electron spins on its axis in an orbital. If paired, the electrons will spin in opposite directions.

Electron Configuration Quiz Electron Configuration Quiz 1. Identify and define the four quantum numbers. 2. How many sublevels (types of orbitals) exist on the third energy level? 3. a. Determine the electron configuration of a neutral Br atom and include the orbital notations. b. How many unpaired electrons does Br have? c. How many valence electrons does Br have?