What does electricity mean please explin it easy

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Agas initially at p1 = 1 bar and occupying a volume of 0.5 liter is compressed within a piston–cylinder assembly to a final pressure p2 = 4 bar. (a) if the relationship between pressure and volume during the compression is pv = constant, determine the volume, in liters, at a pressure of 3 bar. (b) repeat for a linear pressure–volume relationship between the same end states. reference

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?