Answer all the following questions by putting a circle around a letter A.B.C or D
1. Air contains about
A. 3% carbon (IV) oxide.
B. 4%noble gases.
C. 21%oxygen
D. 69% nitrogen​

Respuesta :

Answer:

C. 21%oxygen

Explanation:

Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.