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. .

Electrons in Atoms 1. Using Bohr’s model illustrate and label the subatomic particles in the following neutral atoms: a. Li-4 b. C-14 c. Na-24 2. What do you know about electrons in atoms?

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. (2n2 Rule) http://micro.magnet.fsu.edu/

Electron Properties and Arrangement Chapter 5 Due: Bohr’s Atomic Model Worksheet Objectives: Identify the properties of electrons. Understand how electrons are arranged in atoms. Understand how electrons move in atoms. . 4

Bohr’s Atomic Model Worksheet Check For: All atoms are neutral atoms. Remember electrons should be placed on energy levels (rings) around the nucleus. Limited number of electrons on each energy level, 2n2 Rule Ex. nitrogen atom

Electrons and Light Particles Electron Properties: Very tiny particles Extremely small masses Move at very high speeds (3.0x108 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. *Electrons move around the nucleus in different shaped paths. Erwin Schrodinger

Electron Movement Ground state: lowest energy level for an electron Photon: light particle that contains energy Excited state: movement of electron to higher energy level

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

ICP :Electron Properties 11.13 Infinite Campus Update: Electromagnetic Spectrum Analysis Questions Objectives: Identify properties of electrons. Understand how electrons move in atoms. Distinguish between atoms based on their electron arrangement. Homework: Read thru lab and complete pre-lab questions. Electron Arrangement Worksheet

ICP:Bell Ringer .1. What is the maximum number of electrons on the 5th energy level? Illustrate how an electron can move up and down energy levels within an atom. a. What is electromagnetic radiation? b. What are the three wave-like properties scientist use to distinguish between classes of electromagnetic radiation?

Electron Movement Ground state: lowest energy level for an electron Photon: light particle that contains energy Excited state: movement of electron to higher energy level

Electromagnetic Radiation Spectrum Electromagnetic Spectrum : Divides light particles into regions based on their wave-like properties. a. Relationship b/w wavelength and frequency? Relationship b/w wavelength and energy emission? 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 Frequency (Hz) : how many waves pass a certain point per second. Hz. =Hertz = (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.

Electromagnetic Spectrum Analysis 1

Electromagentic Spectrum Analysis: Check-Up What light particle region emits the least amount of energy? As wavelength increases for a wave, what happens to amount of energy emitted? Sketch a line graph illustrating the relationship (direct or inverse) between wavelength and energy? 4. Does a yellow light particle or a blue light particle have a smaller wavelength. Explain your answer.

Electromagnetic Spectrum Analysis Direct Relationship: Move in the same direction. Inverse Relationship: Move in different directions. Which graph represents direct and which represents inverse? www.shelovesmath.com 

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

ICP : Electron Properties 11.13 Infinite Campus Update: Wave-Like properties Analysis Qts. (8pts.) Objectives: Identify properties of electrons. Understand how electrons move in atoms. Distinguish between atoms based on their electron arrangement. Homework: Complete data and conclusion questions. 21

Flame Test Lab Purpose: Observe evidence of electron movement when chemicals are added to a flame. Procedures: Goggles must be worn at all time. Do not dip wooden sticks in different solutions. Data Modifications: Include Sr2+ solution and Sn2+ solution Mark out following columns:frequency and energy

Flame Test Lab Post-Lab Questions: What direction is the electron moving when the flame turns color? Explain. Was the flame test a helpful method in identifying the unknown solutions? Explain your answer. Identify which element yielded the coolest color. What is another example you have observed of chemicals producing beautiful colors when they are burned?

Flame Test Lab Post-Lab Questions: What direction is the electron moving when the flame turns color? Explain. Was the flame test a helpful method in identifying the unknown solutions? Explain your answer. Identify which element yielded the coolest color. What is another example you have observed of chemicals producing beautiful colors when they are burned?

ICP: Electron Properties 11.14 Due: Flame Test Lab data and conclusion section. Electron Arrangement Practice Sheet (optional) Objectives: Understand how electrons move in atoms. Distinguish between atoms based on their electron arrangement. Homework: Electron Arrangement and Movement Wksht.

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

Minerals Colors 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.

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

Doppler Effect

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.

Chem ICP: Electron Properties 11.15 Objectives: Identify properties of electrons. Understand how electrons move in atoms. Distinguish between atoms based on their electron arrangement. Quiz over electron properties and arrangement Homework: Read and assess article, “Where do Chemical Elements Come From?” 31

ICP: Electron Properties 11.18 Infinite Campus Update: Midterm grades posted tonight. Flame Test Lab (13pts.) Electromagnetic Spectrum Analysis qts. (8pts.) Electron Properties and Wave Properties Quiz (10pts.) Due: “Where do Chemical Elements Come From?” Objective Identify where color comes from in our natural world. Distinguish between atoms based on their electron arrangement. 32

“Where do chemical elements come from?” 1. Where do elements come from? 2. How are elements made? 3. What helps astronomers determine the composition of stars? 4. Briefly summarize a section from this article that you found most interesting. Explain why.

Emission Spectrum Emission Spectrum =Reveals what photons are emitted during electron movement. Ex. Hydrogen Light chemed.chem.purdue.edu

Electron Movement Ground state: lowest energy level for an electron Photon: light particle that contains energy Excited state: movement of electron to higher energy level

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.

Emission Spectrums Emission spectrum for each element is unique. 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. Carbon, Oxygen, Nitrogen, & Calcium Heavier elements 2 % Helium 29% Hydrogen 69%