How much gas is there in 100cm3 of air?

What happens in a global convection cell

Which of the following are guidelines to follow for obtaining accurate observations

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge, at the position of the second charge, change if the second charge is doubled? a. the field does not change b. the field strength decreases by half. c. the field strength doubles d. the field strength quadruples