The diameter of an aluminum atom is about 0.24 nm, and the nuclear diameter is about 7.2 fm (femtometer = 10-15 meter). (a) If the atom's diameter were expanded to the length of an American football field (91.44 m) and the nuclear diameter expanded proportionally, what would be the nuclear diameter in meters? (b) Is the saying that "the atom is mostly empty space" confirmed by these figures?