Classification of Matter Properties of Matter Unit 2 – Matter Classification of Matter Properties of Matter

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 decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element Colloids Suspensions

Pure Substances Element composed of identical atoms EX: copper wire, aluminum foil

Pure Substances Compound composed of 2 or more elements in a fixed ratio properties differ from those of individual elements EX: table salt (NaCl)

(suspensions & colloids) Mixtures Variable combination of 2 or more pure substances. Heterogeneous uneven distribution (suspensions & colloids) Homogeneous even distribution ( solutions)

Mixtures Solution homogeneous very small particles no Tyndall effect particles don’t settle EX: rubbing alcohol

Mixtures Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle EX: milk

The Tyndall Effect Colloids scatter light, making a beam visible. Solutions do not scatter light. Which glass contains a colloid? colloid solution

Mixtures Suspension heterogeneous large particles – can see Tyndall effect particles settle (needs to be shaken) EX: fresh-squeezed lemonade

Mixtures Examples: jello muddy water Fog saltwater Italian salad dressing colloid suspension solution

Mixtures vs. Compounds Components may be in any proportion Individual components retain their own identities Components may be separated physically When mixture is formed there is little to no evidence of a reaction Components are in fixed proportions Individual components lose their identities, new set of properties result Components may be separated only chemically When compound is formed there is evidence of a reaction

Physical Separation Techniques Difference in Densities (density column – some objects float in others) Filtration (separate solids from liquids) Magnetism Chromatography Distillation (separation by boiling points)

Separation of a Mixture The constituents of the mixture retain their identity and may be separated by physical means.

Separation of a Mixture The components of dyes such as ink may be separated by paper chromatography.

Separation of a Mixture Distillation

Types of Properties Physical Properties that describe the substance itself, rather than describing how it can change Example: boiling point, color, size, density Chemical Properties that describe the substances ability to undergo changes that transform it into other substances Example: charcoal has the ability to burn in air

Types of Physical Properties depend on the amount of matter that is present. Extensive properties Volume Mass Energy Content (think Calories!) do not depend on the amount of matter present. Intensive properties Melting point Boiling point Density

Changes in Matter Physical Change Change in form or state of matter without altering chemical composition Examples: slicing a banana, boiling water, dissolving sugar Chemical Change Changing substance into new substance by reorganizing atoms…chemical bonds are made or broken Examples: burning, rusting, copper turns green

5 Indicators of a chemical change Color Change Light emitted (glow sticks, candle burning) Temperature change (happens on its own – you don’t supply heat) Precipitate forms (solid from 2 liquids) Gas production (you see bubbles)

Three Phases

Solids Definite shape/definite volume Molecules are tightly packed, but can still move slightly Most Dense state of matter (because particles are the closest)

Liquids Definite volume/no definite shape (takes the shape of its container) Fluid – because it “flows” Particles are not as close as solids, but are more dense than gases

Gases No definite shape or volume Least dense of the 3 states of matter because the particles are far apart

Which state of matter are they?

Phase Changes Freezing (liquid to solid) Melting (solid to liquid) Vaporization (liquid to gas) Condensation (gas to liquid) Sublimation (solid to gas) Deposition (gas to solid) **** Phase changes are PHYSICAL changes!!!!