What do you mean by "heaviest"? If you have a lot of feathers, it weighs more than a little bit of lead! There are two ways to answer this question. One is what is the element with the highest atomic weight, and what is the element with the highest density. The element with the highest atomic weight is the heaviest for the same number of atoms, and the most dense element is the heaviest element for the same volume of material.
Uranium (U) (atomic number 92) is the naturally occurring element with the highest atomic weight. Plutonium might be argued to be the heaviest naturally occurring element, but it many scientists disregard this. A few atoms of plutonium have been detected in naturally occurring uranium, but the trace ammounts were formed by neutron capture where some neutrons released in the natural decay (spontaneous fission) of uranium were captured by some other uranium atoms and transmuted into plutonium.
Ununoctium (Uuo) (atomic number 118) is the heaviest synthetic element, although only a couple of atoms have ever been made!
The most dense element is osmium (Os), which a density of 22.61 grams per cm3 (which is 22.61 times more dense than water!) That's almost twice the density of lead!
See the Related Question below for more information about the most dense elements.
Natural, known or possible?
The heaviest element in the periodic table (known in March 2013) is ununoctium.
Bismuth (Bi) is the heaviest nonradioactive element but the next heaviest is Lead (Pb) and that is much more commonly used. The heaviest element that is naturally occurring, and also usable, though radioactive, is Uranium (U).
Uranium is the heaviest naturally occurring actinide.
If you are talking about element sin the periodic table, it is ununoctium(Uuo)
Uranium
Mercury is the heaviest element at a liquid state.
The heaviest element in the periodic table (known in March 2013) is ununoctium.
The heaviest element that is highly radioactive is Ununoctium, which has an atomic number of 118.
The information in the question 'What is the heaviest element?' should answer this. Access this by the web link below.
Granite.
Bismuth (Bi) is the heaviest nonradioactive element but the next heaviest is Lead (Pb) and that is much more commonly used. The heaviest element that is naturally occurring, and also usable, though radioactive, is Uranium (U).
The heaviest natural radioactive element is Uranium.Man made elements are continuously being made. The latest heaviest superheavyweight man made element to be discovered is element 117 (it is still so new that it hasn't been given a name yet).A little different bit of information about Fermium, a team has captured a piece of its spectrum-the wavelengths of light it absorbs-making it the heaviest element ever to be so measured. It was made in the 1952 detonation of the first thermonuclear bomb. It does not make it as the heaviest element, just the heaviest to have it's light spectrum captured.
Now californium is considered as the heaviest naturally occurring chemical element.
The heaviest element that can be produced prior to supernova is Iron (Fe).
This element is francium.
To the right!
hydrogen