You might have heard that you can light a fire with a magnifying lens. The magnifying lens accomplishes this by focusing all the light into a single point. What causes this to occur? Write a small paragraph to explain this phenomenon

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present