CHEM 1104 Lecture Notes - Lecture 4: Atomic Theory, Ernest Rutherford
Document Summary
Could mean single atom of an element. Could mean atoms of an element are present in some form. Each element has 1 or 2 letter symbols, first letter is always in caps. Symbol usually is first and second letter of name or sometimes is taken from greek root. Most natural materials are mixtures of pure substances. A given compound always has the same composition regardless of where it comes from. Elements are made of tiny particles called atoms. Atoms of one element can combine with atoms of other elements to form compounds- a compound always has the same composition, number, and types of atoms. Atoms can not be created nor destroyed- a reaction simply changes the way they combine. Expresses the types of atoms and number of each type in a unit of a given compound. The number of each type of atom is indicated by a subscript. When only one is present don"t add a one subscript.
