This document defines and classifies different types of matter. It describes elements as substances made of single atoms and compounds as bonded groups of elements. Pure substances include elements and compounds, while mixtures contain two or more substances mixed without chemical bonding. Mixtures can be homogeneous, appearing uniform, or heterogeneous, with distinct phases. Special types of mixtures include colloids, ores, alloys, and plated metals. The document provides examples to illustrate each classification of matter.

1. Classification of Matter Matter Pure Substances Mixtures Elements Compounds Metals Nonmetals Metalloids Noble Gases Ionic Molecular Homogeneous Heterogeneous Solution Acids Bases Salt Solutions Alloys Suspension Colloid Physical Changes Chemical Changes

2. Elements : matter that is made up of one kind of atom Examples : - metals such as copper ( Cu (s) ) or mercury ( Hg (l) ) ( monatomic ) - nonmetals such as helium ( He (g) ), oxygen ( O 2(g) )( diatomic ) , ozone ( O 3(g) ) ( triatomic ) , iodine ( I 2(s) ) , sulfur ( S 8(s) ) , phosphorous ( P 4(s) ) ( polyatomic ) Compounds : substances that are made up of groups of elements chemically bonded and arranged in a specific manner Pure Substances

3. Special Compounds : Minerals : Oxides: an element or compound that occurs naturally in the earth Example : salt ( halite ) a compound formed by combining at least one element with oxygen Example : Fe 3 O 4(s) – rust ( metal + oxygen ) CO 2(g) – carbon dioxide ( nonmetal + oxygen )

4. There are two types of compounds: Ionic Compounds : Molecular Compounds : formed by combining metallic elements with nonmetallic elements Examples : - sodium chloride – NaCl (s) - magnesium hydroxide – Mg(OH) 2(s) - aluminum oxide – Al 2 O 3(s) formed by combining nonmetallic elements into a unit called a molecule Examples: - carbon monoxide – CO (g) - water – H 2 O (l) - ammonia – NH 3(g) - wax – C 25 H 52(s)

5. Mixtures ( Impure Substances ) - contain 2 or more pure substances that are not chemically joined together and mixed in any proportion - can be physically separated by filtering , boiling or centrifuging - Example: a container of rocks , sand and water There are two types of mixtures: Homogeneous : - looks completely uniform in composition - has only one phase - usually are solutions Examples : - sugar dissolved in water (solid in liquid) - air (gas in gas) - carbonated water (gas in liquid)

6. Heterogeneous : - does not look uniform in composition - distinctly visible phases Examples : - oil and vinegar salad dressing - chunky peanut butter Special Mixtures : Colloid : falls halfway between a homogeneous and heterogeneous mixture as it looks homogeneous but distinct phases exist upon closer, microscopic observations Examples : - milk (liquid in liquid) - gelatin (liquid in solid) Ore : a rock that has an element that can be obtained for profit Examples : - iron ore – Fe 2 O 3(s) - bauxite – Al 2 O 3(s)

7. Alloy : a mixture of at least two elements , at least one of which is a metal , melted together uniformly Examples : - steel – iron and carbon - stainless steel – iron, carbon, chromium and manganese Plated Metals : - a metal object that has been coated with another metal Examples : - Nails may be coated with zinc and steel cans are coated with tin to prevent corrosion . - Some dinner utensils are coated with silver to look more attractive .