Which is the correct order, from simplest structure to most complex, of these particles?
a. atom, diatomic element, molecule, compound
b. diatomic element, atom, compound, molecule
c. compound, molecule, diatomic element, atom

The simplest indivisible particle is called the atom. So, this should be the simplest structure.. This is followed by the diatomic element which is a combination of two identical elements. Next, is the molecule which is composed of a group of atoms or same elements.. Finally, the most complex structure is the compound which consist of at least two elements. Thus, the answer is A. 

30litre of li2o is 1.0002mole approximately 1 mole

Ithink its solid. hope this