Answer:
a. P2O7 - This is a covalent compound. P and O have similar electronegativities and they form a covalent bond between them, rather than an ionic bond.
b. SnBr2 - This is a covalent compound. Sn and Br have different electronegativities, but they still form a covalent bond due to their relatively small difference in electronegativity.
c. Fe(OH)2 - This is an ionic compound. Fe has a higher electronegativity than O and H, so it tends to donate its electrons and become positively charged. This results in the formation of ionic bonds between Fe and OH.
d. Cl3O8 - This is a covalent compound. Cl and O have similar electronegativities, so they form covalent bonds rather than ionic bonds.