Idon't understand any of this:
calculate the percent ionic, the percent covalent, and the bond length (in picometers) of a chemical bond between phosphorus and selenium.
phosphorus—atomic radius: 109 pm; covalent radius: 106 pm; ionic radius: 212 pm.
selenium—atomic radius: 122 pm; covalent radius: 116 pm; ionic radius: 198 pm.
a. 2 percent ionic, 98 percent covalent, 222 pm
b. 98 percent ionic, 2 percent covalent, 410 pm
c. percent ionic, 96 percent covalent, 222 pm
d. 96 percent ionic, 4 percent covalent, 410 pm