Properties and Statesof Matter

Chapters 2 and 3

Classifying Matter

Matter Anything that has mass and takes up space Either a pure substance or a mixture

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Classifying Matter-Pure Substance

Pure Substance Matter that always has exactly the same make-up Either an element or a compound Salt, table sugar, water, gold, aluminum

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Classifying Matter- Pure Substance Element

Something that cannot be broken down into simpler things

Given a 1 or 2 letter symbol on the Periodic Table (C, N, O, Au, Fe)

Carbon, iodine, gold, iron

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Classifying Matter- Pure Substance Compound

Made from 2 or more things and can be broken down into those things

2 or more elements joined in a fixed proportion Water, table salt, sugar

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Classifying Matter- Mixture Mixtures

Contains 2 or more elements with no fixed make-up

Heterogeneous Mixtures Can identify different parts of the mixture Does not look the same all the way through Salad dressing, sand/dirt

Homogeneous Mixtures Substances cannot be distinguished Looks the same all over Tap water, Fruit Punch, stainless steel

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Classifying Matter- Mixtures

Solutions When something dissolves and forms a

homogeneous mixture Salt water, Kool-Aid, Sweet Tea

Suspension A heterogeneous mixture that separates into

layers over time Salad dressing, paint, liquid medicines

“Shake well before using”

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Physical Properties

Physical property Something that can be observed or measured

without changing the material 7 physical properties you need to know

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Physical Properties

Viscosity Liquid’s resistance to flowing Honey = high water = low

Conductivity Ability to allow heat/electricity to flow Iron = good rubber = bad

Malleability Solid’s ability to be hammered without shattering Gold = very glass = not

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Physical Properties

Hardness Ability of something to cut something else Diamond is the hardest substance on Earth

Melting Point Temp. where a substance goes from a solid to a liquid

Boiling Point Temp. where a substance gores form a liquid to a gas

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Physical Properties

Density (D) A substances’ mass divided by its volume

Measured in either g/mL or g/cm3

Remember: 1 mL = 1 cm3 !!! Things that are more dense will sink, Things that

are less dense will float

V

mD

Density

(g/mL or g/cm3)

mass

(g)

Volume

(mL or cm3)

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Physical Properties

A rock has a mass of 12 g. If it has a volume of 50 mL, what is the rock’s density?

A block has a density of 0.005 g/cm3. If the block has a volume of 56 mL, what is the block’s mass?

A graduated cylinder has 13.4 mL of water. When a marble, with a density of 6.2 g/mL, is dropped in the cylinder the water level rises to 34 mL. What is the marble’s mass?

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Using Physical Properties

Physical properties are used for: Identifying a material Choosing a material for a specific purpose To separate the substances in a mixture

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Separating Mixtures

Filtration Separates materials based on the size of their

particles Using a coffee filter

Distillation Separates things in solution based on boiling points Making moonshine

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Chemical Properties

Chemical property A property that produces a change in something’s

composition Something is changing into something else

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Chemical Properties

Flammability Ability to burn in the presence of oxygen Different elements burn different colors Think fireworks!!!

Reactivity How quickly something combines with other

things

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Physical vs. Chemical Changes Physical Change

Some properties of a substance change, but the substance is still the same

Shredding paper, breaking glass, ice cube melting

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Physical vs. Chemical Changes Chemical Change

When a substance reacts and forms one or more new substances

The composition of the matter changes

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Physical vs. Chemical Changes Evidence of a chemical change:

Change in color Copper roof -> green

Production of a gas See bubbles forming

Formation of a precipitate Forms a solid

Temperature change Production of light

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States of Matter

There are 5 states of matter (phases of matter) We only care about 3 of them

Solid Liquid Gas

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States of Matter- Solids

Solid Something with a fixed shape

and a fixed volume Particles are very close

together and vibrate

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States of Matter- Liquid

Liquid Something with no fixed shape

but a fixed volume Particles are free to move around Also called a fluid

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States of Matter- Gas

Gas Something with no fixed shape

and no fixed volume Particles spread apart to fill the

space available

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States of Matter- Other

Plasma Exists at high temperatures and high pressure Stars

Bose-Einstein Condensate (BEC) Exists near absolute zero at very low pressures Solid acts as a single particle

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Behavior of Matter

Kinetic Theory of Matter All particles of matter are in constant motion The state of matter depends on the amount of

motion Originally developed to describe gases

Kinetic Energy The energy an object has due to motion More Speed = More Kinetic Energy

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Behavior of Matter- Gases

Particles move so fast that they are not attracted to each other

Particles move in a straight line until they hit something Act like billiard balls

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Behavior of Matter- Gases

Kinetic Theory of Gases The motion of a gas allows it to fill a container of

any shape or size 3 main points

Particles in a gas are in constant, random motion The motion of 1 particle is not affected by the motion of

other particles, unless the particles hit each other Forces of attraction between particles are ignored

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Behavior of Matter- Liquids

Particles move slower than gases Each particle is attracted to the others Fight between a particle’s constant motion

and the attraction to the other particles

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Behavior of Matter- Solids

Particles are extremely attracted to each other They move very little

Vibrate back and forth in the same spot

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Changes of State (Phase Changes) Phase Change

A reversible physical change A substance goes from 1 state of matter to another

6 common phase changes Melting and Freezing Vaporization and Condensation Sublimation and Deposition

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Changes of State (Phase Changes)

Gas

Solid Liquid

Sublimation

Deposition

Melting

Freezing

Vaporization

Condensation

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Changes of State- Energy

When you heat something up you give it energy And the temperature goes up

UNTIL it changes to another state! When something goes through a phase change, the

temperature stays the same. The heat you add is breaking the attraction

between particles and pushing them away from each other

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Changes of State- Energy

Solid- Temperature is going up

Melting- Temperature is

staying the same

Liquid- Temperature is going up

Changes of State- Energy

Temperature is not changing during melting, but heat is added

Temperature is not changing during boiling, but heat is added

Changes of State- Energy

If you have to add energy, the phase change was endothermic Melting, Vaporization, Sublimation

If you have to take away energy, the phase change was exothermic Freezing, Condensation, Deposition

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Changes of State- Melting and Freezing

Melting Some molecules in a solid,

gain energy to overcome attractive forces to become a liquid

Freezing Some molecules in a liquid,

start to slow down and become attracted to each other as a solid

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Changes of State- Vaporization and Condensation Vaporization

Some molecules in a liquid, gain energy to overcome attractive forces to become a gas

Heat of Vaporization The amount of energy needed to move

from a liquid to a gas Evaporation

Changing a liquid to a gas at temperatures below the boiling point

Spilled water “disappears” after a few hours

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Changes of State- Vaporization and Condensation

Condensation Some molecules in a gas, start to slow down

and become attracted to each other as a liquid The outside of your cold drink, on a hot day

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Changes of State- Sublimation and Deposition

Sublimation Some molecules in a solid,

gain energy to overcome attractive forces to go to a gas

Dry Ice (carbon dioxide)

Deposition Some molecules in a gas, start to

slow down and become attracted to each other as a solid

Frost on cold windows

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