To find this wavelength, we work with the equation of (momentum) = (Planck's Constant)/ (wavelength). Momentum is the mass of the atom multiplied by the speed of the atom. Manipulating the variables gives: Wavelength = (Planck's Constant)/(Mass*Velocity). Plugging in the proper values for each gives: (6.626*10^-34)/(1.67*10^-27)*(425), leading to a value of: Wavelength = 0.00933*10^-7 m, or 933 pm when rounded to 3 significant figures.