A small gas laser of the type used in classrooms may radiate ...

[go.lag]

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW. If the wavelength of the emitted light is 642. nm, how many photons are emitted per second?
 
  What will be an ideal response?

Question 2

For life to have existed continually on the Earth for the past 4 billion years, the oceans must have been
 
  A) completely liquid for this entire time
  B) frozen for most of this time
  C) partially liquid for most of this time
  D) partially frozen for most of this time

[Tonyam972]

Answer to Question 1

6.5  1015

Answer to Question 2

C

[go.lag]

Both answers were spot on, thank you once again

[Tonyam972]

Great! Please up vote