100 because 99.9999 nearest to any number on there would be 100
There are 13 protons because the atomic number (the number in the top left corner) represents the number of protons. Then, to find the number of neutrons, you take the number of protons and subtract it from the atomic mass (the number on the bottom) when it is rounded. The number of electrons is the same as the protons when the atom is neutral
Sin=opposite side/hypotenuse
cos=adjacent side/hypotenuse
tan=sin/cos or opposite/adjacent
