What are "forbidden lines"? Briefly describe how they form
What will be an ideal response?
Forbidden lines are certain lines in the spectra of emission nebulae that are never seen in the spectra of excided gas. When excited gas jumps between certain energy levels, it happens very quickly—in the order of 10^-8 to 10^-7 seconds. On rare occurrences, electrons get stuck in one of these metastable levels before it falls to a lower level and emits a photon of the corresponding energy. Unless the gas has extremely low density, collisions between atoms will disturb electrons caught in metastable levels long before they can make a transition downward and emit a photon producing forbidden lines.
You might also like to view...
Contrast the probes dispatched by Galileo and Cassini in destinations
What will be an ideal response?
(a) What is the wavelength of the peak of the blackbody radiation curve for something at 3,000 kelvins (the temperature of the filament of a light bulb)? (b) What type of EM wave is this?
A charge of 12 C passes through an electroplating apparatus in 2.0 min. What is the average current in the apparatus?
A) 0.10 A B) 0.60 A C) 1.0 A D) 6.0 A
Circular Motion of Charges: An electron is accelerated from rest through a potential difference of 3.75 kV. It enters a region where a uniform 4.0-mT magnetic field is perpendicular to the velocity of the electron. Calculate the radius of the path this electron will follow in the magnetic field. (e = 1.60 × 10-19 C, melectron = 9.11 × 10-31 kg)
A. 1.2 cm B. 2.2 cm C. 3.2 cm D. 4.2 cm E. 5.2 cm