According to the valence-bond model, what atomic orbitals overlap to form each of the following chemical bonds? a) The H–Br bond in HBr b) The I–I bond in I2 c) A C–F bond in CF4 d) The C–H bond in HCN e) A C–Cl bond in COCl2 f) The C–C bond in acetic acid (the molecule on the right) g) The C–O single bond in acetic acid