Unit 3 Matter and Its Transformations What is chemistry? (Introduction to Chapter 1) Physical and chemical properties (1.8) Physical and chemical changes (1.8) Classification of matter (1.9)
What is Chemistry? (Intro to Chapter 1) Matter anything that occupies space and has a mass (1.8) Chemistry the study of matter and its transformations (Introduction to Chapter 1)
Physical and Chemical Properties (1.8) Physical property a physical characteristic or behavior of the material Examples: boiling point, hardness, color Chemical property describes how the material reacts with (or doesn t) with other types of matter Examples: iron rusts in moist air, hydrogen and oxygen react violently, neon does not react with anything
Physical and Chemical Changes (1.8) Physical change a change in the appearance of a substance without changing its chemical identity or composition Examples: melting ice, cutting a piece of wood in half Chemical change a change in the chemical identity of matter into other substances that are different Examples: hydrogen and oxygen react to form water, a piece of iron rusts,
Classification of Matter (1.9) With over 18 million characterized compounds, categorization is important to provide a framework for study This initial classification system provides a good starting point As you might imagine, there are subclassifications under many of these basic groupings
States of Matter (1.9) Three common states of matter (plus a bonus): Gas takes shape of container, flows easily, compressible Liquid takes shape of container but with a flat top, flows easily, not very compressible Solid retains shape, does not flow appreciably, not very compressible (A bonus state: plasma a stream of charged particles this is the stuff of plasma TV)
Particle Level Description of States of Matter Gas: Particles far apart Particles moving rapidly Notice that as the temperature decreases the particles get closer together Liquid: Particles close together Particles moving slowly Particles more ordered than gas, but not as much as solid Solid: Particles close together Particles only vibrating Particles very ordered Images are screen shots from States of Matter simulation PhET Interactive Simulations University of Colorado http://phet.colorado.edu
Pure Substances and Compounds (1.9) Pure substance has a definite fixed composition that does not vary from one sample to another Examples: pure copper, pure water Mixture variable composition that can be different from one sample to another Examples: salt water, air, sand and water mixed together
Further Classification of Pure Substances Pure substances can further be categorized as: Elements substance which cannot be broken down into simpler substances by chemical means Compounds chemical combination of two or more elements
Periodic Table the elements A sample periodic table - if it s a known element it is on here. Compounds are chemical combinations of multiple elements. A large portion of our course will be involved with studying the periodic chart. Periodic table from common.wikimedia.org
Further Classification of Mixtures Mixtures can further be categorized as: Homogeneous all parts of the mixture have the same composition and appearance Examples: sugar dissolved in water, air, a pinch of salt dissolved in water Heterogeneous appearance is not the same throughout Examples: sand in water, oil in water
Summary of Classification of Matter Matter Pure Substances Mixtures Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures