Which element has atoms that can form halide ions?
(1) iodine (3) strontium
(2) silver (4) xenon

Option (1) is the correct answer.

Explanation:

Halides or halogens are the species that belong to group 17. Elements of group 17 are fluorine, chlorine, bromine, iodine and astatine.

Where only astatine is radioactive in nature.

And, only the elements of group 17 are able to form halide ions by gaining an electron from the donor atom.

Silver is a transition metal and hence, it is a d-block element. Xenon is a noble gas and belongs to group 18.

Strontium is a group 2A element and it does not form halide ions.

Thus, we can conclude that iodine element has atoms that can form halide ions.