Why do molecular bands only occur in the spectra of the coolest stars?
What will be an ideal response?
Because molecules in cool stars are not subject to the violent collisions that would break them apart in hotter stars.
You might also like to view...
A solid lead cylinder 0.6-m in diameter and 0.6-m long, initially at a uniform temperature of 121°C, is dropped into a 21°C liquid bath in which the heat transfer coefficient h cis 1135 W/(m2 K). Plot the temperature-time history of the center of this cylinder and compare it with the time histories of a 0.6 m-diameter, infinitely long lead cylinder and a lead slab 0.6 m-thick.
GIVEN
• A solid lead cylinder dropped into a liquid bath
• Cylinder diameter (D) = 0.6 m
• Cylinder (L) = 0.6 m
• Initial uniform temperature (To) = 121°C
• Liquid bath temperature (T?) = 21°C
• Heat transfer coefficient h c= 1135 W/(m2 K)
FIND
(a) Plot the temperature-time history of the cylinder center (b) Compare it with the time history of a 0.6 m diameter, infinitely long lead cylinder (c) Compare it with the time history of a lead slab 0.6 m thick
ASSUMPTIONS
• Two dimensional conduction within the cylinder
• Constant and uniform properties
• Constant liquid bath temperature
SKETCH
Where did Thomson's model place electrons in the atom?
a. Studded throughout a positively-charged material. b. Rotating around a positively-charged core. c. Uniformly distributed in the atom. d. Clustered in the center of a positively-charged sphere. e. At the two magnetic poles of the atom.
The Millikan oil-drop experiment demonstrated that:
a. small oil drops fall slowly through the air. b. light beams can be used to illuminate small oil droplets. c. the electronic charge is quantized. d. falling oil droplets reach terminal speed.
The Moon and Sun are approximately the same physical size
Indicate whether the statement is true or false