Which of these observations provides the best evidence that a new substance formed? A.
The balloon is inflated.
B. The balloon is red.
C. There is liquid in the flask.
D. The liquid in the flask is clear.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock