Suppose that a particular chemical substance A is pure contains ...

[ARLKQ]

Suppose that a particular chemical substance A is pure contains no impurities, and that it can be chemically decomposed into two other pure materials B and C. What conclusion can be draw from this?
 
  A) B and C must be elements.
  B) A must be a chemical compound.
  C) A must be an element.
  D) B and C must be chemical compounds.
  E) Nonsense--it is impossible to decompose a pure substance into two other materials.

Question 2

Which of the following is one of the drawbacks of the automobile engine?
 
  A) CO2 is injected into the atmosphere
  B) CO is injected into the atmosphere
  C) the internal combustion engine has none of these drawbacks
  D) the internal combustion engine has all of these drawbacks
  E) low efficiency

[bd5255]

Answer to Question 1

B

Answer to Question 2

D

[ARLKQ]

Excellent

[softEldritch]

Gracias!