posted by Anonymous .
Ok, let's use the following information to very roughly estimate the size of the nucleus. Rutherford, Geiger, and Marsden (his students) fired a beam of alpha particles at a gold foil. The alpha particles had an energy of about 3.70 million electron volts, a charge of +2e, and a mass of about four AMU (one Atomic Mass Unit is 1.66 x 10-27 kg. Gold has atomic number 79.
How close could the alpha particles get to the gold nucleus?
change ev to joules.
work to get close= KE= integral force*dx
the integral is from inf to d, you are looking for d.
KEinJoules= INT kQq/x^2 dx= -kQq/x
and over the limit,
ke in joules= kQq/d solve for d.