CHEM 101 Lecture Notes - Lecture 3: Unified Atomic Mass Unit, Bohr Model, Atomic Number
Document Summary
When you burn a log you don"t just get ash, you get gas and water. You end up with the same mass of stuff as you started. All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements. When two elements form two different compounds, the masses of element b that combine with 1 g of element a can be expressed as a ratio of small whole numbers. All matter is made up of tiny particles, called atoms. All atoms of a given element are similar to one another, and different from atoms of other elements. A particular compound is always made up of the same kinds of atoms, and always has the same number of each kind of atom. A chemical reaction involves the rearrangement, separation, or combination of atoms. Atoms are never created or destroyed during a chemical reaction.
