A theorem can be proven (from axioms or prior theorems), using logic.
A hypothesis can be supported by evidence. The more evidence in support of the hypothesis, the more likely the hypothesis is to be correct. However, you’re always at the mercy of contrary evidence appearing in the future, to reduce the likelihood or even invalidate a hypothesis.
A (mathematical) proof suffers no such vulnerability to future evidence, as long as you hold the axioms of the theory to be true, and as long as there was no flaw in the construction of the proof.
Physical change 1 is the answer
When you say full valence shell, are you talking about a valence electron shell?
I am learning about atoms and i know a little bit
Answer:
F=248.5W N
Explanation:
Newton's 2nd Law tells us that F=ma. We will use their averages always. The average acceleration the tennis ball experimented is, by definition:

Since we start counting at 0s and the ball departs from rest, this is just 
So we can write:

Where in the last step we have just multiplied and divided by g, the acceleration of gravity. This allows us to introduce the weight of the ball W since W=gm, so we have:

Substituting our values:

Where the average force exerted has been written it terms of the tennis ball's weight W.
Answer: a= 37m
Explanation: V= 15 m/s (Velocity) t= 0.41s (time) formula: a= v/t
15 m/s / 0.41 (15 divided by 0.41) = 36.583m
There are 2 significant digits, 36, you look at the third digit, either round up or down in this case up to 36. a= 37m