If element A is in Group 13 and element B is in Group 17, which ions will be formed when A and B react together? A3+ and B2-
A3+ and B-
A+ and B-
A2+ and B-

A3+ and B-

Explanation:

Elements in group 13 have outermost electron configuration, ns2np1 hence they form trivalent positive ions.

Elements in group 17 have outermost electron configuration ns2np5 hence they form univalent negative ions.

This implies that, if element A is in Group 13 and element B is in Group 17, the ions formed are A3+ and B-.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.