ASTR 1020 1st Edition Lecture 3 Outline of Last Lecture I. Motion & EnergyA. Newton’s LawsB. Basic Types of Energy & Laws Outline of Current Lecture I. Atoms & LightA. Atomic TerminologyB. LightCurrent LectureI. Energy & AtomsA. Atomic Terminology- Atomic Number: number of protons in nucleus- Atomic mass number: number of protons and neutrons- Molecules: consists of two or more atoms- Energy level transitions- Electrons in atoms are restricted to particular energy levels: Quantum Theory- The only allowed changes in energy are those corresponding to a transition between energy levels.B. Light- Properties of Light Waves- Wavelength: distance between two wave peaks- Frequency: number of times per second a wave vibrates up and down- A light wave is a vibration of electric and magnetic fields- Light interacts with charged particles- Continuous Spectrum- The spectrum of a common (incandescent) light bulb spans all visible wavelengths- Emission Line SpectrumThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Thin or low-density cloud of gas emits light only at specific wavelengths that depend on its composition, producing a spectrum with bright emission lines.- Absorption Line Spectrum- A cloud of gas between us and a lightbulb can absorb light of specific wavelengths leaving dark absorption lines.- Chemical Fingerprints- Each type of atom has a unique set of energy levels- Each transition corresponds to a unique photon energy- Downward transitions produce emission lines- Upward transitions produce absorption lines- Properties of Thermal Radiation1. Hotter objects emit more light at all frequencies per unit area2. Hotter objects emit photons with higher average
View Full Document
Unlocking...