Air by weight is composed of ___ oxygen and ___ nitrogen?
A. 21% and 79%
B. 23% and 77%
C. 21% and 77%
D. 23% and 79%
E. None of the above
Answer: B
Air by weight is composed of ___ oxygen and ___ nitrogen?
A. 21% and 79%
B. 23% and 77%
C. 21% and 77%
D. 23% and 79%
E. None of the above
Answer: B