CHEM 1104 Lecture Notes - Lecture 4: Physical Model, Chemical Formula, Fluorine
Document Summary
Chemical formula expresses the type and number of atoms: each atom present is represented by its element symbol, the number of each type of atom is indicated by a subscript. Written to the right of the element symbol: when only one atom of a given type is present, the subscript one is not written. Always use the lowest multiples that you can. Conceptual model= help visualize or understand things that invisible or concepts that can t be seen. It is in the center of the atom. Isotope= atoms with the same number of protons but different number of neutrons. Mass number= (a) the sum of the protons and neutrons. In a group all the elements have very similar chemical properties. Noble gases exists by themselves (exists in their pure form) Another exception is the noble metals (gold, silver, platinum). Atoms form ions by gaining or losing electrons.
