matter & chemistry - mr. celia's science...

Matter & Chemistry

OK, you’ve probably seen the

Bill Nye video and have learned

that matter is everything and all

stuff. That’s right. Everything

around you is matter. In fact,

anything that has weight and

takes up space is matter.

Write it down:

• Matter – Anything that has mass and

volume.

• All objects are made of matter.

Forms of matter

• Matter comes in three common forms or phases:

*SOLID *LIQUID *GAS

• Two additional, less known phases are:

*PLASMA

*BOSE-EINSTEIN CONDENSATE

Solids • Solids have a definite

shape and a definite volume.

• This means that solids keep their shapes and take up a set amount of space under normal conditions.

• Rocks, ice, salt crystals, & wood are all examples of solids.

Liquids

• Liquids do not hold their shapes; they take the shape of their container.

• Liquids have a definite volume. This means that a liter of water is a liter of water no matter what container it is in.

• Water, Pepsi, orange juice & oil are all examples of liquids

Gases • Gases also take the

shape of their

containers.

• Gases do not have a

definite volume. They

will expand out to fill

the entire container.

(Think of a balloon)

• Oxygen, water vapor,

Carbon Dioxide are all

examples of gases.

Plasma – the weird fourth stage

• A plasma is a gas that is made

of atoms that are electrically

charged (positive and negative

ions). A plasma conducts

electrical currents.

It is estimated that

99% of the matter

in the observable

universe is in the

plasma state

Bose-Einstein Condensate In a B-E condensate,

the atoms in the solid

begin to merge into each

other.

The atoms go from

being trillions of

individuals to one big

clump.

This happens only at a

few billionths of a

degree above absolute

zero.

Think of the M&M’s melted together as

the atoms in a B-E Condensate.

Molecules inside matter

• The molecules inside matter are in

constant motion.

• Speed

• Slower Faster

• B.E.C. Solid Liquid Gas Plasma

Solid

Liquid

Gas

Changing Phase

• The atoms and molecules within matter

are in constant motion.

• The energy that causes this is called

kinetic energy – the energy of motion.

• Atoms and molecules with

more kinetic energy

moves faster and further

apart.

• Atoms and molecules with

less kinetic energy

moves slowly and stay

close together.

• The TOTAL energy in all of the particles in a sample of matter is called Thermal energy.

• Thermal energy depends upon the number of particles in the sample as well as the energy each particle has.

• If you average the total kinetic energy of each individual particle in the sample, you have the sample’s temperature. (This will be discussed later in the unit)

• Matter can change state when thermal

energy is absorbed or released. This is

called, believe it or not, “A Change in

State”

Molecular motion in

Solids / Liquids / Gasses

Ice

Liquid water

Steam

Rephrasing/Reviewing

• Kinetic energy is the energy that causes particles in a sample of matter to move.

• Thermal energy is the total kinetic energy of all particles in the sample of matter.

• Temperature is the average kinetic energy of the particles in the sample of matter.

• When a cold object and a hot object come in

contact, the thermal energy is transferred from

the hot to the cool object.

• Thus, when an object is heated, the particles in it

begin to move faster, increasing its temperature.

• Heat is defined as the movement of thermal

energy from a warmer object to a cooler one.

Phase change diagram

Solid Liquid Gas

Phase change diagram

Solid Liquid Gas

Melting Evaporation

Condensation Freezing

Sublimation

Crystalization or desublimation

Add Heat Add Heat

Remove Heat Remove Heat

Vocab Review • Melting: Solid becoming a liquid. Add energy.

• Evaporation: Liquid becoming a gas. Add energy.

• Freezing: Liquid becoming a solid. Remove energy.

• Condensation: Gas becoming a liquid. Remove energy.

More vocab . • Sublimation: Solid becoming a gas, skipping the

liquid phase. Add energy.

• Crystallization or Desublimation: Gas becoming

a solid, skipping the liquid phase. Remove

energy.

• General Terms:

• Solidification: to become a solid.

• Liquefaction: to become a liquid.

• Vaporization: to become a gas.

Sublimation and Crystallization

Properties of matter

• Matter is

described using

three properties

– physical,

chemical, and

biological.

Physical Properties

• Physical properties of matter that

can be observed and measured

using your five senses, without

changing the composition of a

substance.

Physical Properties

• Examples of physical properties include:

• size

• color

• shape and texture

• state of matter

• melting and boiling points

• does it conduct electricity?

• mass, volume, density

More Vocabulary • Solubility: Ability to dissolve in water or

another liquid.

• Malleable: Easily pounded into shapes.

• Ductile: Easily made into wire.

• Viscosity: Ability of a liquid to flow.

Examples: High Viscosity = Corn syrup.

Chemical Properties

• Chemical properties of matter are often

not easily observed. Chemical properties

describe how the chemicals inside the

matter react with other chemicals.

• When trying to figure out the chemical

properties of matter ask yourself some

questions:

Chemical property questions:

• Will it burn?

– Paper will, concrete will not. Therefore, a

chemical property of paper is that it will

burn. A chemical property of concrete is

that it will not burn.

Can I eat it? - You can consume an orange and get

nutrition from it. You can physically eat a

rock, but it does nothing for you. Thus, a

chemical property of an orange is that it is

edible.

Chemical properties

• More often than not,

chemical properties

indicate how the

chemical will react

with other

chemicals. We will

discuss this further

in the unit.

Biological properties

• Biological properties of matter tell whether

it is living, non-living, or dead.

Measuring Matter Matters!

• As we said, physical properties of matter

include measurements.

• The important measurements of matter we

are going to deal with now include Mass,

Volume, Density, and Temperature.

MASS

• Mass: A measurement of the amount of

matter inside an object.

• Mass is often thought of being the same

as weight. This is not true. Weight

depends upon the gravitational force

exerted upon an object.

• Weight - The downward force exerted on

an object due to gravity.

Mass vs. Weight

• Mass is measured using a balance.

• Weight is measured using a scale.

Volume

• How much soda fits into a 2-liter bottle?

• Why does the tub overflow if it is too full

when you climb in?

Volume

• Volume can answer both of these

questions.

• Volume is the amount of space taken

up by an object OR the amount of

space inside a container.

Volume Facts:

• Volume is measured in some form of liters,

commonly Milliliters (ml).

• Volume can also be measured in cubic

centimeters. 1 cm3 water = 1ml water.

• Many items are sold by volume such as

gasoline, soda, milk, and shampoo.

• The average volume of a bathtub is 40

gallons or 151.4 liters.

Most Important fact!!! • When dealing

with volume, the

number one rule

is: NO TWO

OBJECTS CAN

OCCUPY THE

SAME SPACE

AT THE SAME

TIME!

Volume

• Only the bottom

bags are taking

up space on the

pallet.

• The box and the

soda bottle both

have space

inside them.

Measuring volume

• When measuring volume, you can use

different methods depending upon the

shape of the item.

• If you are attempting to find the volume of

a cubic item, you only need to measure

the length, width, and height of the object

and multiply them (volume = L x W x H)

Measuring with a ruler

Length

Width

Height

Length x Width x

Height

If

L = 10cm,

W= 10 cm, and

H = 10 cm,

what is the volume

of this Rubic’s

cube?

Measuring with a ruler

• 10 x 10 x 10 = 1000 cm3

• The answer is given in cubic

centimeters, cm3.

• Remember: 1 cm3 water = 1ml water.

Measuring irregular shapes

• What if you wanted to find out the volume

of a rock? A Ball? A ring?

Measuring irregular shapes

• To measure an object with an odd or

irregular shape, you cannot use a ruler.

• The method used for finding the volume of

irregular shapes is called the Water

Displacement Method.

• The tools required for this method are a

graduated cylinder and water.

Measuring

irregular shapes • 1) Find a graduated

cylinder that will be large enough to fit the object(s) being measured.

• 2) Fill this graduated cylinder enough so that when placed in the graduated cylinder, the object will be fully submerged in the water.

Measuring irregular

shapes

• 3) After filling the graduated cylinder , record the volume of the water.

• 4) Next, carefully place the object in the graduated cylinder and record the new volume of water.

Measuring irregular shapes

• 5) To find the

volume of the

irregularly shaped

object, subtract the

volume of the water

alone from the

volume of the water

and object.

• What is

the

volume

of this

stone?

Important fact!!

• Meniscus - the

curve seen at the

top of a liquid

because of its

attraction to its

container.

Important fact!!

• A meniscus is what happens when you put

a liquid into a container.

• When you put water in a beaker or test

tube, you see a curved surface.

• With most liquids, the attractive force

between the liquid and the container is

greater than the attraction between the

individual liquid molecules. So the liquid

"sticks" to the side of the container.

Meniscus

Water has a slight electric charge which

causes it to stick to the side of the glass. This

is called the meniscus.

Density

• Density is defined as: An object’s mass per unit of volume. In other words, what is its mass compared to its size.

• An objects density tells us how tightly packed the molecules inside are.

• The more tightly packed the

molecules of an object, liquid

or gas are, the more dense

we say they are.

Density

• Density is usually expressed in

grams/milliliters or grams/cubic

centimeters.

• The standard for density is water. Water’s

density is 1 gram/milliliter. That means

that 1 ml of water will have a mass of 1

gram.

Density

• Which item below would be the most dense? Which

would be the least dense?

• WHY?

v

Finding Density

• In order to find the density of an object, you must first know its mass and volume.

• To find density, you divide the object’s mass by the volume and that tells you the density.

• The formula for density is:

Density = Mass/volume or D=M/V

Examples of Density

• The mass of a rock is 20g and its volume

is 4ml. What is its density?

•The mass of a rock is 20g and its volume is 4ml. What is its density?

Sink or Float? • Any object that has a density

of less than 1g/ml is going to float when placed in water.

• Any object with a density that is greater than 1g/ml is going to sink.

• With this in mind, how could you guess the density of a piece of foam?

Oops!

Sink or Float?

• LESS dense objects (things that are less packed together) float on top of things that are MORE dense (more packed together); this includes things like liquids and gases and circumstances like a cheese doodle in rice.

• As long as an object is less dense than the substance it is in, it will float. If an object is too dense it will sink to the bottom.

• The size of the object does not matter!

– *LARGE, light (less dense) object will FLOAT.

– *Small, heavy (more dense) objects will sink.

Formula fun!

• To find density: D=M/V

• To find Mass: M= D x V

• To find Volume: V= M/D

Review

• What tool is used to determine mass?

• What method would you use to find the volume of a basketball?

• What is the formula for finding density?

• How is mass different from weight?

Temperature

• Temperature is the average kinetic

energy of the particles in the sample of

matter.

• As you remember from Bill Nye, all

molecules of any substance are constantly

moving.

• The faster the molecules are moving, the

warmer the substance is.

Temperature

• Scientists use a thermometer to

measure temperature.

Temperature

• Temperature is

measured with

several

different scales.

Temperature - °F

• In the United States, we use the Fahrenheit Scale °F.

• In the Fahrenheit scale, – 320F is the freezing point of water

– 2120F is the boiling point of water.

– -459.670F is Absolute Zero.

Temperature - °C

• the Celsius scale is used by almost every other country 0C

• In the Celsius scale,

– 00C is the freezing point of water

– 100 0C is the boiling point of water.

– -273.150C is Absolute Zero.

Temperature - K

• Scientists use a different scale called the Kelvin Scale K. ( NOTE: the 0 symbol is not used in the Kelvin scale)

• In the Kelvin Scale,

273.15 K is the freezing point of water 373.15 K in the boiling point of water.

0 K is Absolute Zero.

Converting scales

• Kelvin to Celsius °C = K − 273.15

• Celsius to Kelvin K = °C + 273.15

• Kelvin to Fahrenheit °F = K × 9 ⁄ 5 − 459.67

• Fahrenheit to Kelvin K = (°F + 459.67) × 5 ⁄ 9

• Celsius to Fahrenheit °F = °C x 1.8 + 32

• Fahrenheit to Celsius °C = °F - 32 / 1.8

Temperature

• Heat moves in a predictable flow from warmer objects to cooler objects until all objects are at the same temperature.

• In other words, heat moves from high concentration (the heat source) to low concentration. COLD NEVER MOVES!

• Coldness is simply an absence of heat, or slow molecular motion.

• Heat moves in three ways:

• Conduction

• Convection

• Radiation

Movement of Heat - Conduction

• Conduction is the transfer of heat from one object to another through direct contact. (touching)

• Conduction is the simplest form of heat transfer.

Movement of Heat - Conduction

• The rapidly moving atoms of the hot

burner bump against the atoms that make

up the pan, making those atoms move

faster.

Movement of Heat #2 -

Convection • Convection is the method of heat transfer in

liquids or gases by means of currents.

• As particles get heated they start to move faster. As the particles move faster, they move farther apart and the object becomes less dense.

• Less dense objects move to the surface of more dense objects. That explains why the warmer water when swimming is at the top. This also explains how a hot air balloon works.

Convection in a Pot

Water at the bottom

warms, becomes

less dense and rises

to the top.

• As the water at the

bottom of the beaker

gets hotter, it rises to

the top. This makes

the cooler water sink

to the bottom where

It begins to heat.

When it gets hot

enough, it rises and

continues the cycle.

Movement of Heat - Convection • Most likely your home is heated by convection. A

radiator heats up the air near it. When this air rises, the cool air sinks and begins to warm up. When it rises it is replaced again by cooler air.

Conduction and Convection

Movement of Heat - Radiation

• Radiation transfers heat through space to

other objects by infrared waves.

• Heat sources such as the sun or a hot

wood stove send out these invisible

infrared waves.

Movement of Heat - Radiation

The earth receives heat from the sun by

radiation.

Movement of Heat - Radiation

• The heat from the sun can warm the ground

even though it is 186,000 miles away!!

• All things emit

some form of

heat radiation.

This can be seen

with an infrared

camera. Hotter

parts are red, and

cooler are blue.

Movement of Heat - Radiation

Sitting by a

fire, you feel

heat waves.

Conductors and insulators

Conductors

• Some materials readily accept the transfer of heat energy.

• Any material that allows heat to pass through it easily is called a Conductor.

• Heat travels easily through some materials like copper, aluminum, and most metals.

Conductors

• Why are pots and pans made out

of metal and not wood or plastic?

Insulators

• Some materials do not allow heat to pass through very well. These are called insulators.

• The handles on pots and pans are often made of wood and plastic since these materials do not allow heat to pass through them easily.

• Liquids, gases, and most non-metallic solid materials like wood and plastic are good examples of insulators.

Conductor Insulator

• Conductors move heat easily because the

atoms and molecules in a conductor are

generally more dense than insulators.

Buy New Windows!

Why do you think people use

wooden spoons when cooking?

What purpose do the pot holders serve?

Coats, hats, and

gloves trap our body

heat close to us. The

materials inside them

insulate us from the

cold.

Down Coats

• The feathers in a

down coat or

comforter trap the

air molecules in the

many fibers and

prevent heat from

moving.

Insulating your Home saves

Money and Energy!

• Poorly Insulated Home Well Insulated Home

• As air molecules attempt

to move through the

fiberglass, the fibers

slow them down or trap

them, slowing or

stopping convection

currents and the

movement of heat.

• As air molecules attempt

to move through the

empty space, there is

nothing to slow them

down or stop convection

currents and the

movement of heat.

• The better insulated your home is, the less

heat loss that occurs through the walls.

• The less heat loss you have, the warmer

your house stays and the furnace doesn’t

run as often.

• If your furnace doesn’t run as often, you

save electricity, fuel, and MONEY!!

• If you save money, you have more to buy

your favorite science teacher presents!!

Review:

• What is Heat?

• What is temperature?

• How does heat move?

• How is a conductor different from an insulator?

• 98.6 0 F = ___0C? 100 K = ___ 0C?

• What else do YOU feel needs review?

What is Matter made of?

• Matter is composed of tiny particles

called atoms.

• Now would be a good time to view the

exciting, spectacular, Power Point

show entitled “Atoms”