Yes it is for example look at Iodine and Tellurium.
Hope this helps :).
Yes because Na is a metal and Cl is a nonmental, so they criss cross charges, as Na is 2+ and Cl is 2-, 2+ indicates that Na gives AWAY electrons to Cl and the 2- on Cl indicates it receiving electrons. NaCl is table salt and forms a crystal lattice structure, which is why salt is solid at room temperature.
The characteristic that is not descriptive of C, would be D. It forms bonds with only itself. It forms bonds with almost all other nonmetals, present, like H,O,N, etc.
No. of moles = given mass/atomic mass
= 452/40
= 11.3.
Thus, there are 11.3 moles