pretty sure it's both are physical changes.
what?? please reword this
If there is no net force on an object, then the object will <span>maintain it's rate of speed. Basically, net force is the change in an object's motion. If it is stationary and not moving, the object will stay stationary. If the object is moving at a rate of 2 miles per hour, it will constantly continue to move 2 mph because there is no net force.</span>
H ( hydrogen ) is the answer I believe.
