Question 12 2 pts
How could a student determine whether an unknown chemical is an acid? (2 points)
Test the hydrogen ion concentration in the sample.
Measure the boiling point of the sample.
Weigh the sample before and after adding salt.
Determine whether the sample has surface tension,

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?