Neutral hydrogen can be modeled as a positive charge of 1.6 x 10 ^-19 (the proton) surrounded by a spherically symmetric distribution of negative charge having a volume charge density ρ=A x e^(-2r/ao) where ao =5.3 x 10^-11 meter and is called the Bohr radius. The constant A is chosen such that the total amount of negative charge is -1.6 x 10^-19. Compute the value of the constant A with proper units. Find the net amount of charge inside a sphere of radius ao. Compute the electric field at a distance of ao from the nucleus.