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By Sally Anderson
It matters
What is matter?Matter is anything that takes up space and
can be experienced by one or more senses (seeing, hearing, feeling, smelling, tasting)
What is a “state”?The condition or form that matter hasAlso referred to as phase
SolidA state of matter that has a definite shape
and volume.The particles (atoms or molecules) are
packed closely together. The forces between particles are strong
enough so that the particles cannot move freely but can only vibrate.
Solids can only change their shape by force, as when broken or cut.
LiquidA state of matter that has no definite shape,
but has a definite volume – takes the shape of the container.
It can drip.When a solid is heated above its melting point,
it becomes liquid. The molecules have enough energy to move
around and the molecules are farther apart than a solid.
GasA state of matter with no definite shape or
volumeGenerally it can’t be seenIt takes the shape of its surroundingsAlso called a vaporMolecules are quick and far apart
Why properties are important to scientistsWe study the properties of matter to
discover:What is it made of?How does it form?Where does it come from?
Property or characteristicCharacteristics or
qualities; the way something is or behaves
Example: A property of hydrogen, (H), is that it is extremely light in weight.
Other characteristicsIts colorIts shapeIts sizeIts massIts densityIts weightIts molecular structureHow it combines with
other substances
AtomsThe smallest pieces of matter (can’t see them with eyes)The atom is the smallest thing in our bodyDifferent kinds of atoms are called elementsCenter is called the nucleusMade of 3 particles
Nucleus contains protons (+ charge) and neutrons (no charge)
Electrons travel fast around the nucleus
Element
Different kinds of atoms are called elements
A substance that cannot be easily broken into smaller parts
Oxygen is an element that we breathe. Pairs of oxygen atoms join together to form an oxygen molecule.
Periodic table of elementsA table, or grid, showing the periodic
system in which all known elements are ordered by their weights
http://www.chemicalelements.com/http://www.dayah.com/periodic/http://periodic.lanl.gov/default.htm
MoleculeForms when two or more atoms combineAtoms can be the same element (like oxygen) O2Most molecules have atoms of more than one
element CO2; H20Sometimes molecules combine to form a new
molecule (burn coal & carbon atoms in coal combine with oxygen in air to make carbon dioxide)
Physical changesMelting:
Add heat energy to solid, it melts and becomes liquid
Evaporation:Add heat energy to liquid, it evaporates and
becomes a gasFreezing:
Take away heat energy from liquid, it freezes and becomes solid
Condensation:Take away heat energy from gas, it condenses and
becomes liquidIn a physical change into another substance –
water is still water, even if frozen
MeltingTurn from a solid to a liquid by adding heat
energyExample: melting solid gold to turn into
molten gold. Liquid gold can be poured into a mold. Remove heat energy (freezing) and it cools returns to a solid.
Example: NASA engineers have to find a way to protect the shuttle’s aluminum from melting (heat-resistant tiles)
FreezingProcess of liquid changing to a solidReleases heat (take away heat energy)Example: NASA engineers use fuel that is
colder than ice and if ice forms, it would break off and damage the space shuttle (they installed heater)
Evaporate or evaporationThe process of changing a liquid into a gas
or vapor by adding heat energyExample: place a pot on the stove and
some of the liquid will eventually turn into a gas
Example: A puddle after a rain storm evaporates into the air by turning into a gas
Condense or CondensationTo take away heat energy to turn a gas into a
liquidOccurs when water vapor cools (lose heat
energy)Example: water vapor (a gas) can form
outside a cold glass of juice on the table)Example: Water vapor forms liquid dripping
on outside of glass or a car windowExample: On space shuttle, NASA uses liquid
fuels (oxygen and hydrogen) in liquid state by removing heat and they store them in tanks
MassHow much matter is in somethingCan measure the mass, length and
temperature of matter
volumeThe amount of space inside an objectIn a 3 dimentional cube, multiply the length
x width x heightLxWxH
DensityHow much matter something hasMust compare the densities of solids that
have equal volumeIf they have equal volume, the heaviest (or
greatest mass) will be denser
MixingMixing is another type of physical changeExample: (water and oil mix and then
separate) They are still water and oil
DissolvingAnother type of physical changeWhen you dissolve something solid into
something liquid, you make a solutionExample: sugar and coffeeThe sugar is still sugar, even when mixed,
but it is harder to separate the sugar from the coffee than to separate the oil from the water
EnergyPowerExamples: heat energy, light energy, wind
energy, solar energy, nuclear energy,
Potential energyPossible or about to happenExample: The stacked cord of wood has
lots of potential energy because we can burn it to stay warm.
KineticMovement or motionExample: The horse race was filled with
kinetic energy as the horses moved around the track
ViscosityThe amount of friction within a liquidExample: Cold honey is very viscous
because it is hard to pour.If a fluid drips slowly, it is viscous.
Review solidsState
Definition Properties/ characteristics
Mixture change
Temperature and force changes
Solid Matter that can be touched and keeps its own shapeMade of atoms that are really close together
Keep their own shapeIf you add heat, they meltMade of atomsHave color; you can see themIf you apply force, it will breakMade of matter
Chemical reaction when they form together- can’t be separatedChemical change needed to separate it
Increase temperature will change solid to liquid (or gas)Increased pressure and force will change solids