Hi, Assuming that the motion of the hydrogen atom is simple harmonic, its frequency of oscillation, f, is given by the expression: f = 1 / 2π * √(k/m) where k is the force per unit displacement between a hydrogen atom and the carbon atom and the m is the mass of a proton. (i) Show that the value of k is approximately 560 N/m (From previous parts of this question I knew: f = 9.1 x 1013 Hz and the mass was 1.7 x 10-27 I managed to do this question by rearranging and plugging the numbers in the formula However, I am having problems with part (ii) (ii) Estimate, using your answers to (c)(i), the maximum acceleration of the hydrogen atom. I am thinking either F = ma, where F = kx. In this case, the k I got from the previous question would be the constant k, or the F itself? Or use a = -ω2x, using the maximum displacement (I have it from previous part of the question) How should I approach the second part with the F = ma format? Is it possible to tackle the problem in those two ways? Thanks, Peter G.