You boil water in a pot and find that there is a white coating ...

[mp14]

You boil water in a pot and find that there is a white coating lining the inside of the pot after you are done. What happened?
 
  A) The pot must have had a mineral in it already and water stirred it up.
  B) The pot was dirty.
  C) Water evaporated and left bacteria on the inside of the pot.
  D) The mineral precipitated from the water as the water boiled off as steam.

Question 2

Of the 89 naturally occurring elements, how many are needed to account for 99.7 percent of the mass of Earth's crust?
 
  A) 42
  B) 21
  C) 12
  D) 10

[Amiracle]

Answer to Question 1

Answer: D

Answer to Question 2

Answer: C

[mp14]

Excellent

[nanny]

Gracias!