1. The problem statement, all variables and given/known data Make an approximate calculation of the x-ray atomic form factor for He by assuming that its electron density is given by a hydrogenic ground state. 2. Relevant equations Need help with this. 3. The attempt at a solution I attempted to use the hydrogenic model, but could not figure out how to do this. There are additional parts to this question, but I just need a little help on getting started so that I can get this part, and then I can do the parts that follow. Thank you.