Answer:
Zero or +2
Explanation:
The noble gases already have a avplete outermost shell. They are the least reactive elements of earth?
Their normal oxidation number is zero but some have been shown to be reactive.
More friction because it's smooth
In the graph of the force vs the time:
Force is the gradient of the momentum versus the time.
If we get the area under the curve in this graph:
it will be calculated as : force * time
which gives the change in momentum or the impulse.
Therefore, the area under the curve <span>represents the impulse of the force in a graph of force versus time</span>