Classification of Matter

Atom • Smallest particle of an element that still has the properties of that element • Extremely small. Made of protons, neutrons, and electrons

Element • Can’t be separated into simpler substances by a chemical change – Made of only 1 type of atom • Each one has its own symbol on the Periodic Table • Periodic Table organizes them according to their properties

Atoms vs. Elements • Atom – A single one of the element’s basic units • Element – No specific # of atoms – Enough atoms to weigh on a balance (scale) • Silver button is made of many atoms but only 1 element

Compound • Formed when 2 or more different types of atoms combine in a fixed ratio •Any sample has the same # and type of atoms. • Unlike elements, they can be broken down into their component parts by chemical means

Compound • Properties of a compound are usually very different than those of its component elements Sodium chlorine reaction NaCl

Pure Substance Substance made of only one kind of element or only one type of compound • Has a unique set of chemical and physical properties • Elements and compounds are pure substances (by definition)

Mixture • Combination of elements and/or compounds • Can be separated into 2 or more pure substances • Most matter is made of mixtures • Alloy – mixture of metals

Types of Mixtures • Heterogenous mixture – Has visibly different parts – Every sample would have different types and amounts of ingredients

Types of Mixtures • Homogenous mixture – No visibly different parts – Every sample would have the exact same type & amount of ingredients, regardless of where in the mixture it came from – AKA “Solution”