It is possible by the intermediate of nuclear reactions at high energy - see the preparation of the transfermium artificial chemical elements.
Atoms combine to form new atoms in the cores of stars. It is possible but quite difficult to combine them in atom smashers on this planet. That is how the trans Uranium elements have been produced.
Hydrogen- the only atom smaller
Yes. For example, one sodium atom and one chlorine atom combine to make sodium chloride, commonly known as table salt. Two hydrogen atoms and one oxygen atom make water.
One potassium atom can combine with one chlorine atom to form potassium chloride.
Atomic Fusion
The two atoms that combine are a metal atom and an oxygen atom.
create a new atom :D
Nuclear fusion
nuclear fusion
One carbon atom can combine with two oxygen atoms to form carbon dioxide (CO2).
Two hydrogen atoms and one oxygen atom combine to form one water molecule.
Two atoms of lithium will combine with three atoms of oxygen to form lithium oxide, with the chemical formula Li2O. Each lithium atom can donate one electron to each oxygen atom, resulting in a stable compound.