(Solved): Draw the mechanism arrows for both propagation steps for the radical addition of HBr to the alkene. ...

Draw the mechanism arrows for both propagation steps for the radical addition of HBr to the alkene. When drawing single-headed radical arrows, this software requires that they meet at one atom (not in space between atoms like you may do in class). In the second box you will need to draw the first product and another reactant. In the last box you will need to draw an additional product.

Think about the definition of a propagation step: it starts with a radical species and ends with a radical species. Did you show the radical electron arrows meeting at an atom? Do all curved arrows start at an electron-rich site and point toward an electron-poor site? Does the overall number of atoms remain consistent from step to step? Did you specify the correct regiochemistry?