Answer:
1.BaCO3 2.MgBr2 3.aluminum and oxygen 4.Potassium chloride
Explanation:
The answer is Na-F. The F has highest electronegativity among these elements. So we need to find the element with smallest electronegativity. And this element is Na.
Has only 7 electrons so it want to bond with other elements so its very reactive and unstable. Hope this helps
