Example :

If you use the subscript (aq) (=aquaris) , this means that the substance is in a solution.
Subscripts:
-aq-this means that the substance is in a solution
-s-this means that the substance is a solid(or precipitate)
-l-this means that the substance is a liquid
-g-this means that the subtance is a gas
A Timeline<span> on </span>Atomic Structure<span>. 400 B.C. Democritus' </span>atomic theory<span> posited that all matter is made up small indestructible units he called </span>atoms<span>. ... 1803 John Dalton proposed that elements consisted of </span>atoms<span> that were identical and had the same mass and that compounds were </span>atoms<span> from different elements combined together.</span>
They have microscopes to see small objects such as atoms and molecules