Osmium is the most dense element.
The density rho of Hahnium (Dubnium) is still unknown. The density of Osmium is rho = 22,610 kg/m3 or 22.61  g/cm3.
iridium osmium platinum plutonium
There are many elements that are heavier than iron, including lead, gold, platinum, osmium, uranium, etc. Look at the periodic table of the elements.
Any one element can ONLY have a single fixed number of protons. Th only element with a number of protons that sits between 50 and 75 in group 17 of the periodic table is Iodine (I), with 53 protons.
If "heavier than" in the question is interpreted to mean "has an atomic mass greater than", the answer is nitrogen
No, atomically Iron is a heavier element
Osmium and iridium are both heavier than gold.
rhenium
The density rho of Hahnium (Dubnium) is still unknown. The density of Osmium is rho = 22,610 kg/m3 or 22.61  g/cm3.
iridium osmium platinum plutonium
Osmium is much denser than an elephant. Which is heavier depends on how much elephant and how much osmium you're talking about. An elephant-sized pile of osmium would weigh over 20 times as much as an elephant-sized elephant would.
There are many elements that are heavier than iron, including lead, gold, platinum, osmium, uranium, etc. Look at the periodic table of the elements.
Note that a higher atomic mass does not necessarily imply a higher density (it does tend to work that way, but there are lots of counterexamples, and for example both osmium and iridium are considerably denser than the much heavier... in terms of atomic mass... uranium). So depending on what you mean by "heavy", the answer might be slightly different.
copper
Iodine itself is an element, not an ion. It forms anions rather than cations.
Rhenium
Iodine itself is an element, and therefore it has no ingredients other than protons, neutrons, electrons, and atoms.