Emission Spectra Lab

Common Core Connection Today I will be able to: Explore how the photoelectric effect creates atoms with unique atomic spectra Identify the anatomy of electromagnetic waves Informal assessment – monitoring student interactions and questions as they complete the lab Formal assessment – analyzing student responses to the lab and exit ticket Common Core Connection Build Strong Content Knowledge Reason abstractly and quantitatively Use appropriate tools strategically

Lesson Sequence Evaluate: Warm-Up Explain: Emission Spectra Notes Engage/Explore: Emission Spectra Lab Elaborate: Star Spectra WS Evaluate: Exit Ticket

Warm-Up Write the abbreviated electron configurations for the following: Au Br- What is wrong with this abbreviated configuration for Cl? [He]2s22p63s23p5 Take out the worksheet you completed for homework

Objective Today I will be able to: Explore how the photoelectric effect creates atoms with unique atomic spectra Identify the anatomy of electromagnetic waves Explain the quantum model and photoelectric effect. [GT] a. Describe the process that creates atomic spectra. b. Explain the uniqueness of atomic spectra. c. Provide examples of the common applications of atomic spectra, i.e. analysis of a mixture using atomic spectra. d. Describe the relative energies of ultraviolet, visible, infrared, microwave, X-ray, radio, and TV waves. [GT] e. Distinguish between absorption (excitation) and emission of energy. [GT] f. Describe the properties of light. (i.e. wavelength, frequency and energy) g. Calculate the wavelength, frequency and energy for a given electron transition. [GT]

Homework Finish Star Spectra WS Wear closed toe shoes Tuesday STEM Fair Conclusion

Agenda Warm – Up Emission Specta Notes Emission Spectra Lab Exit Ticket

Emission Spectra

According to the Quantum Model… Electrons can be move as waves When electrons release energy, release in the form of light photons

Spectroscopy Study of the emission and absorption of light by atoms and molecules

Anatomy of a wave

Electromagnetic Spectrum

Electromagnetic Spectrum

Anatomy of a wave Wavelength (λ - lambda) – distance between crests in a wave Frequency (v - nu) – number of complete waves passing a point in a given amount of time Amplitude - distance from wave origin to peak or crest

Bohr Model of Atom Electrons are found on specific energy levels When electrons absorb energy, they more to a higher energy level When electrons emit energy, they move to a lower energy level and release light energy

Absorption and Emission of Electrons

Absorption of Energy Photoelectric Effect Electrons are emitted from solids, liquids or gases when they absorb energy from light.

Emitted Light Color is seen if the electron falls back to energy level (n) 2 This is visible light The amount an e- fall determines the frequency of EM radiation released (n = 1 = UV; n = 3 infrared)

Emitted Light No two elements give off the same spectra of colors, because they vary in the number of protons and electrons Emit their own unique line spectra Can be used to identify elements

Line Spectra Emission Spectra of Hydrogen 1 nm = 1 x 10-9 m = “a billionth of a meter”

Continuous vs. Line spectra All wavelengths of visible light are seen Line (Emission) Spectra Only specific bands of color are seen 1 nm = 1 x 10-9 m

Rotate from Station to Station to observe line spectrum of different elements and complete the lab. Emission Spectrum Lab

Complete the worksheet when you finish your lab. Star Spectra WS

Exit Ticket What is happening to the electrons when we see color on the emission spectrum?