If a car was driving 45 miles per hour northeast, and is now driving 30 miles per hour north,
A
the car's velocity decelerated.
B
the car's velocity accelerated.
с
the car's velocity remained unchanged.
D
the car's acceleration is 30 miles per hour.

4al + 3o2 → 2al2o3 what does the "3" in front of o2 stand for? a) it indicates that there are 5 oxygen atoms after you add the coefficient and the subscript. b) it indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule. c) it indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction. d) it indicates that there are 3 separate oxygen molecules in the reaction.