Hey there !
The answer is C. build up of electrical charges by friction
Static electricity is a stationary electric charge, typically produced by friction, which causes sparks or crackling or the attraction of dust or hair.
Hope this helps !
It is supposed to protect the cell from it's surroundings, or from the outside.
<span> this represents the relative overall energy of each orbital, and the energy of each orbital increases as the distance from the nucleus increases</span>
This is how Magnesium appears on the table of elements
12
Mg
Magnesium
24.305
The symbol for it is Mg