Students in class today were given the option of answering the questions below and turning in their answers at the end of class for a little bit of extra credit.

Here are the questions and the answers:
1.   Dendrites, plates, and columns are all names of different types of snow crystals.

2.   Several snow crystals sticking together would form
      a. hail              b. graupel              c. sleet              d. snow

3.   The largest raindrops are only about 5 or 6 mm (~ 1/4 inch) in diameter.  What frozen precipitation particle can get much larger than this?  Hail.

4.   How many 20 micrometer diameter cloud droplets would be needed to make one 200 micrometer diameter drop of drizzle?  The 200 micrometer drizzle droplet is 10 times bigger across than the 20 micrometer cloud droplet.  Volume is length x width x height. So there is a factor of 10 x 10 x 10 = 1000 times difference in volume. 

5.   Is most of the rain in Tucson produced by the COLLISION-COALESCENCE  or the ICE CRYSTAL  process?

6.   Which of the following is found in the greatest amounts in the mixed-phase region of a           cold cloud?
      a. ice crystal nuclei      b. ice crystals      c. supercooled water droplets      d. graupel

7.   What differences are there between condensation nuclei and ice crystal nuclei?  Ice nuclei are much less abundant than condensation nuclei.  Ice nuclei must have a crystalline structure resembling ice.  The same requirement doesn't apply to condensation nuclei.

8.   What is virga?
Rain or drizzle that evaporates before reaching the ground.