Matter I. Forms of Matter

What is Matter? Matter is anything that takes up space and has mass. Mass- amount of material in an object Everything has mass (even air) Weight is due to gravity, and changes from location to location; mass is always constant.

Kinetic Molecular Theory KMT Particles of matter are always in motion. causes thermal energy The kinetic energy (speed) of these particles increases as temperature increases.

States of matter Solid- matter that can not flow (definite shape) and has definite volume. Liquid- definite volume but takes the shape of its container (flows). Gas- a substance without definite volume or shape and can flow.

States of Matter Definite Volume? Definite Shape? Temp. increase Com-pressible? Small Expans. Solid YES YES NO Small Expans. Liquid NO NO YES Large Expans. Gas NO NO YES

B. Four States of Matter Solids very low KE - particles vibrate but can’t move around fixed shape fixed volume

B. Four States of Matter Liquids low KE - particles can move around but are still close together variable shape fixed volume

B. Four States of Matter Gases high KE - particles can separate and move throughout container variable shape variable volume

B. Four States of Matter Plasma very high KE - particles collide with enough energy to break into charged particles (+/-) gas-like, variable shape & volume stars, fluorescent light bulbs, CRTs

Actually there is a 5th phase BOSE-EINSTEIN CONDENSATE — a condensate that forms near absolute zero that has superconductive properties; Example: supercooled Rb gas

Types of Matter Pure Substance- a particular kind of matter that is uniform (all the same) and has a definite composition. They are classified as elements & compounds Water and gold Mixture- more than one kind of matter; has a variable composition

Can it be physically separated? A. Matter Flowchart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically broken down? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element Colloids Suspensions

Pure Substances Element composed of identical (1 type) atoms Cannot be broken down to simpler substances EX: copper wire, aluminum foil

Pure Substances Compound composed of 2 or more elements in a fixed ratio Can be broken down by chemical means properties differ from those of individual elements EX: table salt (NaCl), sugar (C6H12O6)

Pure Substances Law of Definite Composition A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions Elements can combine in different ratios to form different compounds.

Two different compounds, each has a definite composition. Pure Substances For example… Two different compounds, each has a definite composition.

Mixtures Can be separated into at least two pure substances; variable composition. Every part keeps it’s own properties. Heterogeneous- mixture is not uniform in composition Chocolate chip cookie, gravel, soil. Homogeneous- same composition throughout; called “solutions” Kool-aid, chocolate milk, salt water

Mixtures Variable combination of 2 or more pure substances. Heterogeneous Homogeneous

Mixtures Solution Homogeneous very small particles no Tyndall effect Uniform in appearance very small particles no Tyndall effect Tyndall Effect particles don’t settle 1 phase present at a time EX: rubbing alcohol

Solutions Continued Mixed molecule by molecule Can occur between any state of matter gas in gas; liquid in gas; gas in liquid; solid in liquid; solid in solid (alloys), etc.

Solutions continued Like all mixtures, they keep the properties of the components. Some can be separated easily by physical means: rocks and marbles, iron filings and sulfur Other methods: distillation- takes advantage of different boiling points (physical properties) Chromatography: takes advantage of solubility.

Mixtures Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle Variable composition 2 or more physically distinct phases may be present EX: milk

Mixtures Suspension heterogeneous large particles Tyndall effect particles settle Variable composition 2 or more physically distinct phases may be present EX: fresh-squeezed lemonade

Compound or Mixture Compound Mixture Made of one kind of material Made of more than one kind of material Made by a chemical change physical change Definite composition Variable