MatterPSc.2.1: Understand types, properties, and structure of matter.

What is matter?

Anything that has mass and volume (takes up space)

Examples: wood, candy, water, ice

Forms of energy such as electricity, heat, and lightning are NOT matter according to the definition.

Classifying Matter

Matter

Pure substance

Element

compound

Mixture

heterogeneous

homogeneous

Pure Substance

Has a fixed chemical compositionExamples: water (H2O) Hydrogen (H2)

The composition of a pure substance is the same all of the time. Sugar is a pure substance because its chemical composition is the same no matter what manufacturer produces it.

Pure Substances Can Be Classified as either element or compound. Element: composed of only 1 kind of

atom. You will find elements listed on the Periodic Table of Elements;

Elements have a single symbol that is either one or two letters.

If the symbol is two letters, the first one is ALWAYS capitalized and the second is ALWAYS lower case.

Example: carbon (C), Helium (He)

Elements can be classified as metals, non-metals or metalloids (semi-metals)The periodic table of elements

organizes the elements into metals, non-metals and metalloids.

Metals

Metalloids

Non-metal

s

Compound

a substance formed from two or more different elements that have undergone a chemical reaction to combine them

Has a chemical formula that contains the symbols of each element in the compound

Example: oxygen (element) combines with hydrogen (element) to create a water molecule (H2O)

Mixtures

Have a composition that varies depending upon the amount of substances combined or mixed together

Example: sugar mixed with tea; ice cream sundae; soil

Mixtures can be classified according to how well the substances are mixed. Heterogeneous mixture: substances

do not mix well; you can see different layers or substances settle out to bottom

Homogeneous mixture: substances are well mixed and look like one substance; you don’t see layers or particles settling to the bottom

Homogeneous and heterogeneous mixtures can be classified as……

Solutions: homogeneous mixture where particles are evenly dispersed throughout

Suspension: heterogeneous mixture where particles are somewhat evenly dispersed

Colloid: heterogeneous mixture of tiny particles that are intermediate in size suspended in a liquid, solid or gas; will scatter light (tyndall effect)

Classify the following……

Orange juice with pulpLithium (Li)Carbon monoxide (CO)KoolaidChocolate chip cookiesSugar water

Solutions (homogeneous) Solutions are homogeneous mixtures of substances.

When a substance dissolves in another substance it is described as soluble because there is an attraction between the particles of the solute (substance being dissolved) and the solvent (the substance doing the dissolving.

Insoluble: the substance will not dissolve in the solvent because there is a lack of attraction between the particles.

Solutions can be described in the following manner:

Unsaturated: there is more solvent and less solute so there is “room” for more solute to dissolve

Saturated: the solvent has dissolved the maximum amount of solute: “no more room”

Supersaturated: there is more solute than the solvent can dissolve and the excess settles out

Temperature is very important in the process of dissolving. Usually at high temperatures, more solute can dissolve. The EXCEPTION is gases. More gas particles can dissolve if the temperature is low.

States (Phases) of Matter

Kinetic Molecular Theory

All matter is composed of tiny, constantly moving particles.

The kinetic energy of these particles increases with more motion.

As kinetic energy (and motion) of particles increases, the temperature of the matter increases.

Solids

Have a definite shape

Have a definite volume

Have low Kinetic energy because the particles are packed so close together that they vibrate but don’t move around

Crystalline solids: particles are arranged in a repeating geometric pattern

Diamonds, sugar, salt

Amorphous solids: particles do not have a defined pattern

Wax, glass

Liquids

Have a definite volume

Measure using a graduated cylinder

DO NOT have a definite shape

Take the shape of the container that its in

Have more Kinetic energy than liquids because particles are not as closely spaced; the particles can move past each other but are still close

Gases

DO NOT have a definite shape

DO NOT have a definite volume

Have very high Kinetic energy

Particles are tiny and spread very far apart and move very fast.

Changes in State or Phase Require the addition (endothermic) or removal (exothermic) of heat or

energy

Kinetic energy is due to motion of particles. Potential energy is related to the space between particles. Change Name Process Kinetic

EnergyPotential Energy

Solid to liquid

Melting Endothermic

increases decreases

Liquid to solid

Freezing Exothermic Decreases increases

Liquid to gas (vapor) at the boiling point

Vaporization Endothermic

Increases Decreases

Gas to liquid Condensation

Exothermic Decreases Increases

Solid to gas (vapor)

Sublimation Exothermic Increases Decreases

Gas to solid deposition Endothermic

Decreases IncreasesEvaporation is also a liquid to gas change but the substance does not have to be boiling.

**melting point = freezing Point temperature

Phase Changes

Solid

Liquid

Gas

Melting Vaporization

Condensation

Freezing

Liquid

Sublimation

Melting Vaporization

Deposition

Condensation

Solid

Freezing

Gas

Water

Waterand IceIce

Water and Steam

Steam

-20

0

20

40

60

80

100

120

0 40 120 220 760 800

Heating Curve for Water

Temperature is constant during a phase change!

boiling

melting

Vaporization versus Evaporation

Vaporization: Substance must be heated to its boiling point

Takes place throughout the entire liquid

The attractive forces between molecules is very low.

Fast and vigorous process

Evaporation: Substance does not have to be at its boiling temperature

Takes place at all temperatures

Slow process

Takes place only at the surface of the liquid

Depends on external factors such as surface area, wind, humidity, and temperature

https://www.youtube.com/watch?v=7zo10Yxicn1

Properties of matter

Physical property: a characteristic that can be observed about a sample of matter without changing the identity of the matter

Magnetism, density, color, shape, weight, volume, mass, phase or state

Physical properties can be used to separate mixtures of substances

Sand and water mixture can be separated by filtering through filter paper or strainer. The sand will be trapped by the filter paper and the water will flow through.

A mixture of sand and iron can be separated using a magnet because iron is magnetic and will be attracted to the magnet. Sand is not.

A mixture of salt and water can be separated by boiling the mixture. Water evaporates and the solid salt will be left behind.

A mixture of oil and water can be separated because oil and water have different densities and the oil will float on top of the water because it is less dense.

Chemical property: characteristics of a substance that indicate how it will interact with other matter or undergo a specific chemical change

Flammability: will it ignite or burn

Reactivity: will it react with other substances

Lithium is highly reactive with water but not oil.

Helium is not flammable but oxygen is.

Physical Changes in Matter

Physical changes are changes in the form or phase of a substance but the identity is still the same Properties remain the same

Physical changes are reversible; ice can be melted and liquid water results however the chemical makeup is still the same H2O

Physical properties can be used to separate mixture

Examples: dissolving a substance in another one

grinding something into smaller pieces

cutting a piece of wood

any phase or state change: melting, boiling, freezing, sublimation, condensation, deposition

Chemical changes in Matter

Chemical changes will change one substance into a completely different Ewith new chemical and physical properties

Cannot be reversed Rusting, burning, tarnishing, decomposing, rotting, oxidizing

Can be recognized by the following signs: Gas or bubbles are produced

Odor changes

Precipitate (a solid substance) forms usually when 2 liquids are combined

Energy change occurs (heat and/light produced, temperature changes (gets hotter or colder)

Color changes: something clear turns to another color; a color disappears; a color changes to a different color