Answer:
The SI units for energy is Joules.
Explanation:
The left side of the periodic table has elements that have less number of electrons in the valence shell.
These elements loose electrons easily.These elements appear as metals or metalloids in nature.These are hard solids.Their inter molecular forces are very strong.
The right side of the periodic table has elements that have more number of electrons in the valence shell.
These elements gain electrons easily.These elements appear as non metals most of which are gases.Their inter molecular forces are weak.
I believe the answer is californium because it is used in most metals and is very strong and expensive like gold and silver
