1. The problem statement, all variables and given/known data an electron is moving at 2.5 x 105m/s. Find the electron's De Broglie Wavelength. 2. Relevant equations De Broglie relates wavelength of electron waves to momentum of the electron by lambda = h/p where h is planck's constant. 3. The attempt at a solution given the velocity above of 2.5 x 105m/s, I multiplied that velocity by 9.109 x 10-31kg to get momentum (p). from there i used (4.136 x 10-15eVs) / (9.109 x 10-31kg)(2.5 X 105m/s) This gives me 18162257108.4 m which is off by many orders of magnitude from the 180pm that the book lists as the answer. Can someone please show me where i'm going stupid on this one? Thanks!