Beyond Labz 2

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School

Dallas County Community College *

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Course

1411

Subject

Chemistry

Date

Jan 9, 2024

Type

pdf

Pages

5

Uploaded by CaptainWaspPerson700

12/11/23, 6:00 PM Beyond Labz 2.0 Assessment https://worksheets.beyondlabz.com/multiembedq.php?id=5476-5477-5478-5479-5480-5481-5482 1/5 Click here to erase all data entry on this page
12/11/23, 6:01 PM Beyond Labz 2.0 Assessment https://worksheets.beyondlabz.com/multiembedq.php?id=5476-5477-5478-5479-5480-5481-5482 2/5 Energy Levels Purpose To understand the origins of Quantum Theory using a spectrometer to observe the emission spectrum of several gases. Connections to What You Already Know About in Life Mercury vapor is used in fluorescent light tubes. The emitted visible light is not very bright for just the mercury vapor, but when scientists examined the full spectrum for mercury they saw that there is an enormous emission in the ultraviolet range (UV). This light is sometimes called black light, and you may have seen it in glow-in- the-dark displays. Fluorescent light tubes are coated with a compound that will absorb UV and emit the energy as visible light with all the colors of the rainbow. All colors together create white light which is why fluorescent light tubes emit very white light. Laundry detergents contain small amounts of a compound that absorb UV light and emit visible light. These compounds allow advertisers to claim whiter and brighter whites and colors . If you attend an event using black lights, you may have seen your white socks or white shirt “glow”. Vocabulary Emission spectrum, spectroscopy, fluorescent Background The classical picture of atoms would allow electrons to be at any energy level. According to this classical model, when electrons are excited and then fall back down to the ground state, they emit light at all wavelengths and the emission spectrum would be continuous. In the 1800s scientists found that when a sample of gas is excited by an alternating electric current, it emits light only at certain discrete wavelengths. This allowed for the development of spectroscopy which is used in the identification and analysis of elements and compounds. Even though scientists found spectroscopy very useful, they could not explain why the spectrum was not continuous. The explanation of this was left to Niels Bohr, a Danish physicist. Bohr proposed that energy levels of electrons are not continuous but quantized. The electrons only exist in specific energy levels. Because of this quantization of energy, excited electrons can only fall to discrete energy levels. You can separate the lines in the full region of an emission spectrum by using an optical prism or a diffraction grating. A spectrometer is an instrument designed to separate the emitted light into its component wavelengths and plots the intensity of the light as a function of wavelength. This assignment illustrates the measurements that helped Bohr develop his quantum model, now known as Quantum Theory. It also illustrates some practical uses for this science. Mercury vapor is used in fluorescent lights and sodium vapor in street lighting. Procedure Section 1 1. To start this activity, click this link for Energy Levels . The lab will load in a new tab. Click back to this tab to read further instructions and complete the questions below. You can follow along with the instructions below in the Procedures tab in the lab.
12/11/23, 6:01 PM Beyond Labz 2.0 Assessment https://worksheets.beyondlabz.com/multiembedq.php?id=5476-5477-5478-5479-5480-5481-5482 3/5 Questions 1. The lab table will be set up with four items. What is the detector on the right? spectrometer 2. What is the metal sample in the center of the table? W 3. A heat source is used to heat the metal sample to high temperatures. What is the temperature of the heat source? 3000 K
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