Which among following element has highest chemical reactivity?
Which among following element has highest chemical reactivity?

1. Be
2. Mg
3. Sr
4. Ba

Solution: Ba

Because of its high reactivity, barium (Ba) is only found in nature in conjunction with other elements. Sulfate and carbonate are the most common compounds formed by barium, but it can also form compounds with hydroxide, chloride, nitrate, chlorate, and other negative ions.