F=ma
F = 148×(85-35)÷20
F = 148×(50÷20)
F = 148×2.5
F = 370N
I can help you do them for yourself :)
Note the atom of the Oxygen is electrically neutral, meaning it has equal numbers of electrons and protons.
So if it gains 2 electrons, it would have excess of 2 electrons, hence its charge would be -2.
Option B.
I believe the answer is D. <span>The hypothesis is revised and another experiment is conducted.</span>