I am not quite sure what you mean with "most complex"; the element with the highest atomic number that occurs naturally (though only in trace amounts) seems to be Californium (#98), although elements up to #118 have been created artificially.
Uranium is the most complex atom that is found naturally in the universe. Uranium has 92 electrons and was originally discovered in 1789.
Uranium, atomic number 92, is the element with the highest atomic number that is found in nature.
Bromine is the most complicated
Hydrogen
Pulutonium
The most abundant element where? It is the most abundant element in Earth's crust. The most abundant element on planet Earth, on the other hand, is iron, while the most abundant element in the Universe is hydrogen.
The most abundant element in the universe is hydrogen.
The lightest and most abundant element in the entire Universe is hydrogen. Hydrogen has an atomic mass of nearly one.
Because hydrogen is the most abundant element in the universe. Also hydrogen was the first element which appeared after Big Bang.
Throughout the entire universe. (It is the most common element in the universe)
Hydrogen is the most abundant element in the universe.
Carbon is the 4th most abundant element in the universe, after hydrogen, helium, and oxygen.
The most abundant element where? It is the most abundant element in Earth's crust. The most abundant element on planet Earth, on the other hand, is iron, while the most abundant element in the Universe is hydrogen.
The most abundant element in the universe is hydrogen.
The most common element in the universe is Hydrogen.
Hydrogen is the most common element in the universe, and in the Sun.
Hydrogen is the most abundant element in the universe.
Hydrogen is the most abundant element in the universe.
Hydrogen is the most common element in the Sun, in most stars, as well as in the Universe in general.Hydrogen is the most common element in the Sun, in most stars, as well as in the Universe in general.Hydrogen is the most common element in the Sun, in most stars, as well as in the Universe in general.Hydrogen is the most common element in the Sun, in most stars, as well as in the Universe in general.
The lightest and most abundant element in the entire Universe is hydrogen. Hydrogen has an atomic mass of nearly one.
The most abundant element in the universe is hydrogen.
Hydrogen (H) is the most abundant element in the universe.