Changes in the Properties of Matter Physical and Chemical

Elevator: Which floor please?

Girl: 3rd underfloor?

Elevator: Thank you.

Boy: Where are all the other stores?

Girl: Well, I don't know really.

But I do know that the store helped Caysie win first prize at the science fair.

Boy: The store did THAT?

Girl: Well, the person who works there did.

Her name is Mrs. Molly Mcqule.

(giggles)

You can laugh if you want,

but weren't you the one that needed help in science class?

Yes, I guess. My grades haven't been all that great.

And we're starting to study matter.

Girl: Mrs. Mcqule

Mrs. Mcqule: May I help you?

Girl: Mrs.Mcqule.. It's me Amanda,

You helped my friend with his science project,

And well Kyle here.

Mrs.Mcqule: As a matter of fact I can.

Kyle: What?

Mrs. Mcqule: The facts of matter.

One second please.

(Weird sounds)

Mrs. Mcqule: Is there something I can show you in matter?

Amanda: Mmm yeah.

My friend Kyle's having some problems in class.

They're studying matter.

Kyle: Yeah. The properties and changes of matter.

Can you help?

Mrs. Mcqule: As a matter of fact I can.

Don't you just love that?

(Jokes around) Matter, facts.. get it?

Ehh nevermind..

Anyway, let's review what matter is.

Amanda?

Amanda: Matter is anything that takes up space..

has mass and has properties that you

can observe and describe.

Kyle: But, what is a property?

Amanda: A property is something special

about an object. That makes it what it is.

Like this bell, it's metal.

Kyle: Oh, I get it.

Mrs. Mcqule: Splendid! Blue star for you.

I think you're really gonna like this.

I just bought the upgrade. (Claps)

Now, let's proceed.

Computer voice: Matter is made up of

elements

or pure substances that are often called

the building blocks of matter.

And these building blocks are made up of

small particles called atoms.

Now each type of matter has its own

physical properties. Which makes it

different from other types of matter.

Physical properties can be measured

or observed without changing the

matter into something else.

Most of these properties remain consant

and can be used to identify it.

Now some properties are common to

or found in all types of matter.

All matter has mass, which is the

amount of matter in an object.

For example, an object with a large

mass feels heavy.

While an object with a small mass

feels light.

So you simply can't tell how much

mass an object has just by looking at it.

But you can measure it.

Mrs.Mcqule: All matter also has volume

which is the amount of space an

object takes up. This ballon for example

has more volume than.. say a

golf ball. Because it takes up more space.

I mean kids, it's just bigger.

And all matter has density. Which is

the property of matter that compares

the mass, the amount of matter.

To volume, the space it takes up.

Kyle: So all matter has is physical properties.

Well what about changes in matter?

Mrs.Mcqule: Patience dear boy. Let's

take a look at physical properties

first and then we'll dive right in and

solve your problem, ok?

The atoms that come together to make

up that matter give it it's particular physical properties.

Computer voice: One physical property that's

found in most matter is that it is,

metallic.

84 out of 112 known elements are metallic.

That's 3/4's.

In fact all elements can be divided into

metallic and non-metallic elements.

Elements like copper, gold, silver, aluminum

iron, and nickel are metallic.

All metals except mercury are solid at room temperature.

Also, most metals look shiny and are

found in the Earths ground.

Most metals are said to be malleable

which means that they can be

hammered into thin sheets.

Or pulled into long thin wires.

Some metals are light, they are bendable

like copper and aluminum.

That are used to make wire.

Some metals like iron are heavy, hard

and very strong.

Kyle: So matter that is metallic is usually

shiny, solid at room temperature,

malleable and strong.

Mrs. Mcqule: You're a quick learner.

Now 28 or 1/4 of all elements are

classified as non-metals and their

properties are very different from the

properties of metals.

Amanda: Like what?

Mrs: Mcqule: Well, most non-metals are

not shiny and can not be hammered into

sheets or pulled into a wire. They are not

malleable they are brittle.

Oxygen and nitrogen are non-metals

that are in the air. (blows)

Carbon, a solid non-metal is dark.

Now that we've established metals and

non-metals. Let's say we take a look at

some of the more exciting physical

properties.

Matter has an physical property called

conductivity.

Computer voice: Conductivity is the

ability to pass energy along from one

particle to another.

There are three kinds of conductivity

electrical, heat and sound.

(background music)

When matter can move electrical energy

from one particle to another it is called

an electrical conductor, metals used to

make wire such as those made of copper

are electrical conductors.

The reason these metals are able to

conduct electricity, is that the electrons

fartest from the nucleus of a metal atom

are only held lightly by that atom

they are free to move to other metal atoms.

This freedom of electron movement,

allows metal to conduct electricity.

Matter that is unable to conduct much

electricity at all is called an

Electric Insulator.

This matter in non-metallic.

In electric insulators, the electrons are

bound tightly to their atoms.

Glass, plastic and rubber are good examples.

(background music)

Some materials can conduct heat very

well.

These materials allow heat to flow

through them easily.

Metals conduct or transfer heat very quickly.

For instance, have you ever noticed

that when a car has been sitting in the

sun, it's metal parts are much hotter than

its plastic parts.

That's because metal conducts heat

better than non-metal plastic.

(background music)

Cooking pots and pans are made of metal.

Because metal conducts heat well.

The heat from the stove is quickly passed

through the pan, into the food.

Voila! The food is cooked.

Other materials insulate against the

passage of heat.

Man: Ooh la la!

Mrs.Mqcule: Which means that they do

not readily permit heat to flow.

(Glass shatters)

Cooking pots should have wooden or

plastic handles to insulate against heat.

So you don't get burned when you touch them.

(background music)

This last kind of conduction is a bit

different.

This is the movement of sound energy.

(Bell rings)

Many metallic substances conduct sound

very well.

But a non-metallic substance, like glass

or even water conduct sound well too.

Matter with a poor ability to conduct

sound is used as sound insulation.

Special ceiling tiles are good examples

of this.

Mrs.Mcqule: Whether or not a substance is

magnetic, is another physical property of

matter.

Objects made from iron and steel are

magnetic.

Plastic is not.

Well we can't mention physical properties

of matter without mentioning chemical

properties as well.

Kyle: Yeah. I'm about to study that in

class.

Mrs.Mcqule: Mmmm, how about a head start?

Computer voice: Chemical properties

describe the ability of matter

to react or combine with

another matter to form a new substance,

a new kind of matter.

Although it's pretty hard to observe a

chemical property.

For example, pyrite and gold look a lot

alike, but pyrite is made of iron and

sulfur atoms.

It has some of the physical properties

of gold, but it's fools gold.

People sometimes use acid to tell gold

and pyrite apart.

The sulfur in pyrite reacts with the acid

to produce a gas gold does not.

Another chemical property is the ability

to burn.

This is called combustibility.

Flame tests can be used to identify

substances based on the color of the flame

they produce when burned.

Barium produces a green flame.

Sodium produces a yellow flame.

And potassium produces a violet flame.

(background music)

And now Kyle as for your request

the changes of matter physically and

chemically that is.

Why don't we start with physical change,

which is a change in state, shape or size

without forming a new substance.

A change in the state of matter is

a physical change.

For example, when water changes state

it looks and feels different, but it is

still water.

Whether it's ice, liquid or vapor.

Let's run with this, shall we?

When you grind peanuts.. you get peanut

butter.

The size and shape have changed, but

you still have peanuts.

Remember a change in size or shape

is a physical change, no new substances

formed.

Other physical changes include mixing

together two or more kinds of matter.

Or separating matter into the different

parts as long as no new substances formed

Most of the objects around us are not

pure substances, but mixtures.

A mixture is two or more parts blended

together, yet they keep their own properties

and do not turn into a new substance.

In some mixtures it's easy to tell

that each type of matter keeps its

physical properties, because you can still

see the individual parts of the mixture.

Examples of this could be salad,

spaghetti, tacos, and trail mix.

In other mixtures the parts are hard to see.

Like sugar or salt mixed with water.

Also, in a mixture you can put the

substances together in any amount.

For example, tea can be very strong

or very weak.

Mixtures can be made of solids, liquids

or gases and can be made with a

combination of different forms of matter.

Air is a mixture of different gases.

Mixtures can also be separated using

their physical properties like size, shape,

color, volume, density and state.

This is called a physical separation.

It's important to remember that subsatnces

that make up mixtures; keep their

physical properties as well as their

chemical properties.

Some mixtures are not as easily separated.

These "hard-to-separate" mixtures are

called solutions.

A solution is a mixture in which

substances are completely blended,

so that the properties are the same

throughout.

The substances are mixed evenly, so they

stay blended.

If you put a spoonful of sugar into a

glass of liquid water and stir; the sugar

seems to disappear and the glass still

contains a clear liquid.

The sugar and the water form a kind

of mixture called a solution.

Although you can't see it, you can tell

the sugar's in the water, because it tastes

sweet.

When the water evaporates, the sugar

will be left behind and you can see it

again.

People drink a lot of types of solutions,

like tea, coffee, fruit juices, and soft

drinks.

When one material forms a solution

with another material; we say it dissolves.

The substance in a solution dissolve or

separate into their most basic particles.

Molecules that are too small to be seen.

As sugar dissolves in water, molecules of

solid sugar are pulled away from

eachother by water molecules.

Very quickly the sugar molecules

spread to all parts of the solution.

You can no longer see the sugar,

because the very small sugar particles

are mixed evenly with the water particles.

Unlike the mixture of granola, that might

have six raisins in one spoonful

and three in the next.

Any part of the solution is identical to

any other part of the solution.

Some solids dissolve in water and some

do not.

Solubility is the measure of the amount

of a material that will dissolve

in another material.

For example, sugar is soluble in water,

but ground black pepper is not.

Try stirring sand into water, while you're

stirring the sand mixes with the water

but does not dissolve.

When you stop stirring the sand falls

to the bottom of the jar.

The solubility of sand in water is zero.

No amount of sand dissolves in water.

Liquid solutions are usually transparent,

they're evenly colored, and they can

never separate into layers.

Compare the mixture of oil and vinegar,

as in salad dressing to a solution; like

this drink mix.

Also, solutions don't have to be liquid.

They can be solids and gases too.

In the sugar and water solution;

a solid, sugar was mixed with a liquid,

water.

In a bottle of soda, the gas carbon dioxide

is dissolved in or spread evenly

throughout the liquid.

When you lift the top off the bottle,

you can see thousands of bubbles of

carbon dioxide gas start to rise through

the liquid an into the air.

Mixtures of metals are solid solutions.

Brass is a solution of zinc and copper.

It is made by melting two metals

together.

Gases can form solutions too.

Air is a solution of several gases.

Physical changes can sometimes be easily

reversed, but not always.

Melting an ice cube can easily be reversed

by cooling until it freezes again.

Stirring sugar into water can be reversed

by letting the water evaporate.

On the other hand, it would not be

so easy to get peanuts back once they

were all ground up.

Kyle: So if a change seems easy

to reverse, it is more likely to be a

physical change.

Amanda: But not all combinations of

matter can be separated physically into

their parts.

Mrs.Mcqule: Well done.

Now for something really thrilling

chemical changes.

(background music)

Mrs.Mcqule: Unlike the often "easy-to

-reverse" physical changes, chemical

changes don't turn around so easily.

These changes occur when atoms link

together in new ways.

This is called a chemical reaction.

During chemical reactions the atoms in

the substances that were put together,

rearranged to form a new substance with

different properties.

The changes in the linking patterns of the

atoms create the new substances.

These new substances have properties

different from the original substances

from which they were formed.

Sugar is made when the right amounts

of carbon, oxygen, and hydrogen atoms

are mixed.

A chemical reaction can cause sugar to

break apart into it's original elements

or atoms; carbon, oxygen and hydrogen.

There are signals that a chemical change

is happening.

They include a formation of a gas,

a color change, or light and heat changes

caused by the release of energy.

The reaction between baking soda and

vinegar is an example of a chemical change.

When these two materials are mixed gas

bubbles form.

A change in the linking pattern of the

atoms in the liquid vinegar and solid

baking soda, cause a new substance,

carbon dioxide, a gas, to form.

Kyle: Ahh.

One of the signals, a gas was formed.

Computer voice: With a burning candle,

many changes are happening.

Wax melts, runs down the side and turns

solid again, this is a physical change.

However, some of the wax turns into

carbon dioxide gas and steam when it

combines with oxygen in the air.

This chemical change releases enough heat

to make a flame.

Amanda: A heat change!

Computer voice: Rust forms when iron

atoms in steel, react with oxygen from

the air.

The reaction is very complex and needs

moisture to occur.

When iron rusts it turns red or brown.

Kyle: A color change.

Mrs.Mcqule:Yes, but are you sure this

is a chemical reaction? Or a physical

change?

Let's find out.

Rust is powdery and no longer shiny

like iron, it also does not bend like iron,

iron can conduct electricity while rust

does not, rust melts at a much higher

temperature than iron, the density

of rust is much less than the density

of iron and rust does not react with

oxygen as iron does.

So is this a physical or chemical change?

Both: Chemical change.

Mrs.Mcqule: Right, we can see that a

new substance is definitely been formed

and a chemical reaction, has taken place.

Now, rocketships use chemical reactions

that produce lots of heat.

(Rocket launches)

(Astronaut talks)

Mrs.Mcqule; This space shuttles main engines are

powered by liquid hydrogen and liquid

oxygen.

When the oxygen and hydrogen come

together, they make water vapor and

release the energy the shuttle needs to

take off.

A chemical change has happened

because the two substances hydrogen

and oxygen came together to make a

third new substance, water vapor.

Burning is another chemical change.

When wood burns, it turns into or

becomes something else.

It turns to smoke, heat and ash, it isn't

wood anymore.

That's because during burning, particles

that make up the wood, react with oxygen

in the air and change into other

substances such as; carbon dioxide, ash

and water vapor.

Electricity can also cause chemical changes.

If an electric current is sent through

water, a different kind of change takes

place.

Gases are produced, but the gases are not

water vapor, they are oxygen and hydrogen.

The substances that make up water.

When you eat food, chemical changes

take place as you digest it.

Digestion is a series of complex chemical

changes, each consisting of many

chemical reactions.

When you ate breakfast, your teeth will

make no physical change, breaking

the food into smaller pieces

and your saliva was chemically breaking

down the food molecules into smaller

and smaller particles.

In your stomach acids reacted with the

food to further change and make even

smaller molecules.

Finally, in the intestines, more digestive

juices chemically reacted with what used

to be oatmeal to produce the many

different molecules of sugar, protein, and

minerals your body uses to live and grow.

All during digestion chemical reactions

produce new substances with the atoms

of the old substances.

In general, chemical changes are difficult

to reverse.

(driver slams on brakes)

Turning carbon dioxide gas, water,

and sodium acetate back into baking soda

and vinegar would be difficult.

Kyle: And how about changing that

oatmeal back into what my dad poured

into my bowl this morning.

Amanda: Imagine trying to "unburn" toast

or "unspoil" milk.

(bells ring)

Mrs.Mcqule: We've seen and talked about

physical and chemical changes in matter.

But, sometimes it's hard to tell the

difference.

Physical changes are often easy to reverse

but because matter can be changed in size

and shape by being cut, folded, stretched

,rearranged and crumpled without

changing its original properties

it can look very different

Matter can even be melted, frozen or

heated to change its physical state.

And although it looks different, it is

still the same substance.

Let's look at some examples.

Cherry flavored drink powder is pale pink

but turns bright red when you mix it

with water, but the powder has only

dissolved.

It has gone through a physical change

not a chemical change.

Kyle: Oh, I would've thought that the

color change, was a sign of a chemical

change.

Mrs.Mcqule: When you open a cold soft

drink bubbles are produced but a chemical

reaction is not taken place.

The carbon dioxide has simply.. come

out of solution.

Amanda: Another sign of a chemical

change that didn't plan out.

Mrs.Mcqule: If you rub your hands quickly

back and forth across the surface they

become hot, but the heat is due to the

friction, not a chemical reaction.

Kyle: So a heat change sign doesn't

always work either.

Mrs.Mcqule: Cheer up Kyle.

You know the basics about matter and

if you know that.. you can figure out

those tough spots.

You now know the facts of matter.

Kyle: I think I do.

Mrs.Mcqule: So, tell us first what is

matter.

Kyle: Matter is anything that takes

up space, has mass and has properties

that you can observe and describe.

Mrs.Mcqule: There are two kinds of

properties, physical and chemical.

How are they different?

Kyle: Physical properties can be seen

and measured without changing the

matter into something else.

Amanda: Chemical properties are harder

to see because they describe the

ability of matter to react with other matter

to form some.. different matter.

Mrs.Mcqule: What are the three physical

properties that ALL matter has?

Amanda: There are lots of physical

properties, but three of them belong to

all matter; mass (the amount of matter)

that has volume (how much space it takes

up) and density (mass compared to it's

volume).

Mrs.Mcqule: Hmm.. Do you know any other

properties?

Amanda: Sure.

Most matter that is metallic is shiny,

malleable, strong and a good

conductor of heat, electricity and sound.

Some metals like iron are magnetic.

Most matter that is not metallic is

not shiny, malleable, strong and is not a

good conductor.

Mrs.Mcqule: Now, what about changes?

How can you tell a change is physical

or chemical?

Kyle: Physical changes don't make a

new kind of matter, the matter keeps it's

properties, when one kind of matter is

physically mixed with another kind of

matter.. it might look like something new

but the parts can usually be separated.

Amanda: But when there is a chemical

change, the atoms in the matters that

are mixed up together, hook up in new ways

;they change to form a new kind of matter.

Kyle: Sometimes we can see the signs

of a chemical change.

There might be a color change, sometimes

a gas forms, or energy can be released

as light or heat.

But.. you can't always count on those

signals.

Mrs.Mcqule: So, do you feel a little

better on the properties of matter?

And the changes that matter can go

through?

I know I do.

Kyle: (Jokes around) as a MATTER of FACT

I do.

(background music)

Kyle: Where's Mrs.Bailey?

Woman: Oh, she's out today, I'm

substituting.

You're here early.

Kyle: Yes I'm just.. excited about

the test, I guess.

Woman: Ahh the test.. physical and

chemical changes in matter.

Kyle: Yeah.. I hope I do ok.. (gasps)

Mrs.Mcqule: I think you'll do fine.

Just fine.

(♫ Sings ♫)

Both: M is for metric, conversion to a cup

A is for astronaut cause they go to the

moon.

T is for tattertot cause they are really

good.

T is for toddlers cause they go "room

room room".

E is for elephant cause they take up

much space.

R is for radical cause matter's really cool

M-a-t-t-e-r (shouts) Matter!!

Amanda: For more great videos call