2/25/2003 J.Noller 2003

States of MatterStates of Matter

The Effects of Energy on MatterThe Effects of Energy on Matter

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Four States of MatterFour States of Matter

• Matter has many properties. • It can have PHYSICAL properties like

different densities, melting points, boiling points, freezing points, color or smells.

•Physical properties are MEASURABLE•Each chemical has UNIQUE measurable physical properties

• There are also CHEMICAL properties that define matter

•Chemical properties define how a substance combines/recombines with other substances

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Four States of MatterFour States of Matter

‘State’ of Matter = ‘Phase’ of Matter

Phase Change is aPHYSICAL Change

Not a ChemicalChange

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SolidsSolidsOne of the main characteristics of solids is that they hold their own shape

In the same way that a solid holds its shape the atoms inside of a solid are not allowed to move around much. The solid atoms and molecules are trapped in their places. The atoms still spin and the electrons still move but the entire atom doesn't go anywhere. They just kind of jiggle in place.

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Solid to LiquidSolid to Liquid• To change a SOLID into a LIQUID,

you add ENERGY.• HEAT is the easiest energy to find• At a ‘Magic Temperature’ the Solid

turns into a liquid.• This is called the MELTING POINT• If you remove heat, the liquid turns

back into a solid• Then it is called a FREEZING

POINT• MELTING POINT is a measurable

physical property

J.Noller 2003

LiquidsLiquids

• Liquids are an in-between phase of matter. They are right between solids and gases.

• One characteristic of a liquid is that it fills the shape of any container. Has volume, but NOT Shape

• Liquids cannot be compressed.

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Liquid to GasLiquid to Gas• Add ENERGY to a liquid and it

becomes a GAS• The special temperature when a

liquid becomes a gas is called the BOILING POINT.

• The reverse is the CONDENSATION POINT.

• You might hear the term VAPOR. Vapor and gas mean the same thing. The word vapor is used to describe gases that are usually found as liquids (like water).

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GASGAS• Gas is everywhere. • There is something called the

ATMOSPHERE. That's a big layer of gas that surrounds the Earth.

• Gases are random groups of atoms. Gases are really really spread out and the atoms and molecules are full of ENERGY, bouncing around constantly.

• Gases can be COMPRESSED because there is so much room between atoms/molecules.

J.Noller 2003

GasesGases

The special temperature when a liquid becomes a gas is called the BOILING POINT. When you cool a gas it liquefies. When a gas becomes a liquid the speed and energy in the molecules drop and ATTRACTION forces allow the molecules to group together.

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EVAPORATIONEVAPORATION• Sometimes a liquid can be sitting there and its molecules

will become a gas. That's called EVAPORATION. • All liquids can evaporate at room temperature and

pressure. • Evaporation is when there are atoms or molecules

escaping from the liquid and turning into a vapor. • Not all of the molecules in a liquid actually have the same

energy. • The energy you can measure is really an AVERAGE of all

the molecules. • Those with a lot of energy that build up enough power to

become a gas and leave the liquid. When it leaves it has evaporated.

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Gas to PlasmaGas to Plasma

                                                                                 • A plasma can be made from a gas if a lot of energy is pushed inside.

• All of this extra energy makes the neutral atoms break apart into positively and negatively charged ions and free electrons.

• The electrons are pulled off of neutral atoms. • They leave ions and electrons in a big gaseous ball

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PlasmaPlasma• Plasmas are a lot like gases • The atoms are different

because they are made up of free ELECTRONS and IONS of the element.

• You don't really find plasmas too often when you walk around.

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PlasmaPlasma• We said you wouldn't find plasmas

anywhere. But maybe there are some right in front of you.

• Think about a fluorescent light bulb. They are not like regular light bulbs. Inside the long tube is a gas.

• When the light is turned on ELECTRICITY flows through the tube.

• This electricity acts as that special energy and charges up the gas.

• This charging and exciting of the atoms creates a glowing plasma inside the bulb.

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States of MatterStates of Matter

ADD

ADD

ADDMelting PointFreezing Point

Boiling PointCondensation Point

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Measurable PhysicalMeasurable PhysicalPropertiesProperties

•All matter has ‘measurable physical properties’!

•Properties: Atomic Mass, melting point, boiling point, density, electro negativity, polarity, etc.

•The properties are UNIQUE to the element or compound

•If you know the properties, you know the substance!

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Examples of PropertiesExamples of PropertiesElement or Compound

Atomic Weight(AMU)

AtomicVolume

(cm3/mol)

Melting point

K

Boiling point

K

Density(g/cm3)

Hydrogen 1 14.4

14.06 K 20.4 K 0.0000899

Water 18 18 273 K 373K .997

Sugar (Sucrose)

342   190°C   1.587

Gold 197 10.2 1337.63 K

3081 K 19.32

Silver 108 10.3 1235.1 K

2428

K

10.5

Lead 207 18.17 600.702 K

2024 K 11.34

Salt (NaCl) 58 ? 801°C 1465°C 2170 kg

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Density LabDensity LabSubstance Mass Volume Density

1 Pc Clay      

2 Pc Clay      

1 Stick      

2 Sticks      

1 Penny      

2 Pennies      

1 Crayon      

3 Crayons