1. The problem statement, all variables and given/known data Sodium ions (Na+) move at 0.844 m/s through a bloodstream in the arm of a person standing near a large magnet. The magnetic field has a strength of 0.259 T and makes an angle of 59.0° with the motion of the sodium ions. The arm contains 95.0 cm^3 of blood with a concentration of 2.50 X 10^20 Na+ ions per cubic centimeter. If no other ions were present in the arm, what would be the magnetic force on the arm? 2. Relevant equations F=qvBsin(theta) 3. The attempt at a solution F= q(.844m/s)(.259T)(sin59) Thats as far as I have gotten. I am guessing that I need to use the volume of blood and concentration of ions to find the charge but I am not sure how to do so and have looked all through my text book for help.