Which is a common way for a scientific calculator to show the number
below?
3 x 10^9

O A. 93
O B. 9E3
O C. 9 x 10^3
O D. 3EP

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of

Which symbol can be used to indicate the pressure at which a chemical reaction is carried out? 25°c 2 atm pa