When many of the atoms or molecules in a sample have been excited into a metastable state, a(n) ______________ has occurred

a. ultraviolet catastrophe
b. population inversion
c. coherent emission
d. incoherent absorption


b

Physics & Space Science

You might also like to view...

A 4.00 kg mass is moving in a circular path with a constant angular velocity of 5.00 rad/sec and with a tangential velocity of 5.00 m/sec. The centripetal force on the mass is

A. 90.0 N. B. 100 N. C. 125 N. D. 169 N. E. 200 N.

Physics & Space Science

If you toss a coin straight upward while in a train moving at constant velocity, the coin will land

A) as if you were at rest. B) in front of you. C) in back of you.

Physics & Space Science

Magnetic confinement is used in controlled fusion experiments to control a plasma

a. True b. False Indicate whether the statement is true or false

Physics & Space Science

If the Earth and all things on the Earth are continually radiating energy, why doesn't everything get progressively colder?

What will be an ideal response?

Physics & Space Science