Planck proposed: E = n h ν n = integer number of photons ν = frequency of emitted light h = Planck’s constant = 6.626 × 10 − 34 J-s c = λ ν c = speed of light = 3.00 × 10 +8 m/s Problem 12-1: What is the energy of a single green photon ( λ = 523nm)? Problem 12-2: What is the energy of one mole of green photons?
Name_________________________ Section _________ Copyright 2011-2018 Chemistry Department PSU 15 Chapter 1.6 Light Energy TOPIC 13 – REAL-WORLD EXAMPLES Problem 13-1: Give examples of ways that these types of light are encountered in real-world situations. Based on your experience, is this type of energy dangerous or not? (As an example, the entry for visible light is already done.) λ Common Use & Dangerous or Not??? Energy: High or low? Interaction with Matter (Demo!) Gamma 0.01 nm (small) Ionizing radiation N 2 + h ν → N 2 + + e − X-Ray ~ 1 nm Ionizing radiation O 2 + h ν → O 2 + + e − Ultraviolet 10 – 400 nm Breaks chemical bonds O 3 + h ν → O 2 + O Visible 400 -750 nm Room lighting: Light emitted from light bulbs NOT dangerous In the middle of EM spectrum Adds heat ( ↑ T) Translation (KE) Electronic transitions Infrared μ Causes vibrations Microwave mm-cm Causes rotations Radio 1- 1000 m (long) Flip nuclear spin Simulation of what happens at a molecular level when light interacts with matter.
Name_________________________ Section _________ Copyright 2011-2018 Chemistry Department PSU 16 Chapter 1.6 Light & Climate science TOPIC 14 – Climate Science Problem 14-1: A. All of the energy on earth comes from the sun. What fraction (%) of the sunlight reaches the