Joseph Proust

The idea that elements combine in fixed proportions to form compounds

Chemical Formula

indicates the elements present in a compound and the actual numbers for each

molecular formula

The actual ratio in nature of atoms in a compound

empirical formula

The smallest, simplest form of atoms in a ratio

H2O

2 Hydrogen atoms: 1 oxygen atom IN ONE ATOM OF THE COMPOUND OF WATER

macroscopic world

what we see

atomic and molecular world

the particles that compose matter

example of an atomic element in nature:

potassium by itself

example of a molecular element in nature:

hydrogen being found in a diatomic way

ionic compounds

nonmetal and a metal

molecular compounds

compounds with two or more nonmetals

Avogadro's number:

6.022 x 10 ^23

precipitation reaction:

Two liquids combine to form a solid

state changes like solid into liquid form are

NOT EVIDENCE OF A CHEMICAL REACTION