H Propagation Step (1)HN The chlorine atom collides with a methane molecule and abstracts (removes)a H, forming another free radical and one of the products(Hcl) H +:C HC·+H-Cl Chapter 4Chapter 4 6 Propagation Step (1) The chlorine atom collides with a methane molecule and abstracts (removes) a H, forming another free radical and one of the products (HCl). C H H H H + Cl C H H H + H Cl =>