The hydroxyl radical is found in the atmosphere in very low abundance, approximately 10' molecules per cm'. Copper is a face-centred cubic metal having a lattice parameter of 361 pm. Assuming a sticking coefficient of 0.5, calculate how long it takes for a monolayer to form on a 1 cm? copper surface (100) exposed to hydroxyl radicals under atmospheric conditions (P = 1 atm, T = 25 °C