Question

A destructive lab assistant constructs thin sheets of Beryllium (Be); each sheet is a single atom thick. Microscopically, these sheets form a triangular lattice: 3 Be atoms sit on the corners of equilateral triangles, and this structure repeats in 2D.

Be's atomic mass is about 1.5 × 10^-26 kg, each sheet is made up of about 4 moles, and a Be-Be bond has ε ≈ 2.1 × 10^-22 J.

The assistant wishes to break a Be sheet by dropping it. They approximate the bond energy by counting only nearest neighbor bonds. From what height, at minimum, should they drop it? (Your answer must be in units of meters!)

You may neglect air resistance and edge effects, and you may assume all of the energy from the collision goes into breaking the bonds. Take g to be 10 m/s².

Answer 1