ISCI 101 Lecture Notes - Lecture 5: Chemical Change
Document Summary
Pure substance: material that is uniform and has a fixed compensation at the nano-scopic level. Element: pure substance made up of only one kind of atom; e. g. helium gas. Atom: smallest particle of an element that retains the characteristics of the element. Chemical compounds: pure substance made of atoms of different elements combined in specific ways. Physical properties: those that can be observed without changing the identity of a substance. Chemical properties: those that result in chemical changes. Structural formulas: chemical formulas show connection between atoms in molecules with a straight line.