Which of the following elements is a metal?

carbon (c)

iodine (i)

iridium (ir)

radon (rn)

The tendency of an element to loose an electron is called metallic property of that element. 1.Carbon has 4 valence electrons hence it's difficult to loose electrons. 2.Iodine has 7 valence electrons hence it will gain 1 electron and form octet. 3. Iridium has 2 valence electrons so it will loose electrons and gain stability. 4. Radon has 6 valence electrons hence difficult to loose electrons. So Iridium is the correct answer. Ping me for any questions. :-D