CHEM 1A03 Chapter 3: Chem 1A03 - Unit 3 Photoelectric Effect

51 views5 pages

harlequindinosaur92

5 Nov 2016

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

itsmealionline and 39769 others unlocked

CHEM 1A03 Full Course Notes

Verified Note

35 documents

Document Summary

1: discuss the wave particle duality of light and of the electron, and describe the experimental. The visible spectrum ranges form purple (390nm) to red (760nm) Gamma, y-ray, x-ray, uv, visible, infra-red, micro-wave, radio wave. Energy is directly related to the frequency of waves (e v) We see the visible spectrum due to cone-shaped cells in our eyes which act as receivers tuned to the wavelengths in this narrow band of the spectrum. Each quantum of energy released from an atom is a photon. The energy of each photon of light is equal to it"s frequency multiplied by plank"s constant. H = 6. 62607004 10-34 m2 kg / s. Single light strikes a metal surface to which a voltage is applied. If ephoton > threshold energy of the metal, electrons are ejected with kinetic energy. X2 number of electrons ejected = x2 the current. The initial energy must be able to overcome the threshold (hv0)

Related Questions

Answer #2

Use a ruler to calibrate the spectral limits in the figure above. In other words, what are the right and left limits in nm, and what is the equation that converts distance on this page in cm to spectral units of nm? This âcalibrationâ will help you with the next item.

Use the NIST Atomic Spectral Database to assign the three bright spectral lines in the hydrogen spectrum.

Abstract This physical chemistry laboratory exercise will have students work with provided emission spectra for several elements and data collected on the NIST Atomic Spectral Database. First, students will develop a method for calculating what wavelengths of visible light are associated with the most intense spectral lines in the provided visible emission spectra. Then, the NIST Atomic Spectral Database will be accessed in order to identify select properties associated with the four most intense spectral lines. Introduction The emission process can be described in two general parts. Initially, energy is absorbed by an atom, and its electrons can be moved into higher energy (excited) states from their ground state The excitedrelectrons then "relax" and drop back to their ground state. Energy lost during an electron's retaxation process is emitted as a photon. Recall that the energy of a photon is photon upper E lower Where Ephoton is the energy of the photon that is emitted when the emitter drops from an upper energy state to a lower energy state, h is Planck's constant, c is the speed of light, and v is the wavenumber. Remember that the length units should match for c and v This is a good time to revisit a few concepts. Atoms and molecules possess discrete energy levels their energy levels are quantized and not continuous. Using eq 7.1, it is possible to determine the energy associated with a specific excited state to ground state transition if we can determine the wavelength of emitted light. Also keep in mind that there are selection rules that limit the type of transitions we can expect to observe. All of these points are reflected in an elemental or ionic emission spectrum. The visible light spectrum falls within a fairly narrow range of wavelengths, from approximately 400 to 700 nm. Even so, discrete spectral lines are seen in each element's visible light emission spectrum. Each (take some time to reflect on why that would be), each element also has a unique emission spectrum. This provides a diagnostic tool for determining the composition of a sample. As an example, the elements present in celestial objects can be determined by the light that they produce line represents one possible transition. Since each element has unique energy levels Some of the transitions observed in this lab exercise involve d-orbitals. As such, a discussion regarding d-orbitals and related selection rules is necessary at this point. The first goal is to determine which character table should be used. Start by observing the shape and relative orientations of the d-orbitals. Refer to Figure 1 below

CHEM 1A03 Chapter 3: Chem 1A03 - Unit 3 Photoelectric Effect

CHEM 1A03 Full Course Notes

Document Summary

Get access

Related textbook solutions

Chemistry: Structure and Properties

Basic Chemistry

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Principles of Chemistry Molecular Approach

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related Documents

CHEM 1A03 Lecture 3: Unit 3 Module 1: Atomic Structure and Theory

CHEM 1A03 Study Guide - Final Guide: Electromagnetic Spectrum, Threshold Energy, Roygbiv

CHEM 1A03 Lecture Notes - Lecture 3: Work Function, Rydberg Formula, Threshold Energy

Related Questions