54. write a formula for the ionic compound that forms from
each pair of elements.
(a) aluminum and oxygen
(b) beryllium and iodine
(c) calcium and sulfur
(d) calcium and iodine
show work if any

a) Al2O3

Explanation:
Aluminum generally forms Al3+ ions.
Oxygen generally forms O2− ions.

So when the metal and the non-metal bond together they form a neutral compound, i.e. Al2O3
(i.e. 2×3−3×2=0).

The ionic bonding is so strong (due to charge magnitude) in this material that it is reasonably insoluble.

Ci think not