The World of Chemistry: A Matter of State

Summary

El misterio de los tres estados de la materia, gaseoso, líquido y sólido, es explorado en este guion. Se explica cómo la temperatura y la presión influyen en la transformación entre estados, demostrando con experimentos cómo el agua se convierte en vapor y viceversa. Además, se aborda la importancia de la liquefacción de gases como el metano para el almacenamiento y transporte eficiente, y se introduce el concepto de cristales como una forma altamente organizada de la materia sólida, proporcionando una visión detallada de cómo los cambios de estado están intrínsecamente ligados a la energía y el movimiento de partículas a nivel submicroscópico.

Takeaways

• 🌡️ La química comienza con la idea de que la materia puede existir en tres estados: gas, líquido y sólido, y estos estados pueden cambiar entre sí.
• 💧 Los gases son tenues y comprimibles, mientras que los líquidos son fluidos y deformables, y los sólidos son más compactos y a menudo más densos.
• 🔥 La temperatura es un factor clave en la transformación de la materia de un estado a otro, como se muestra cuando el agua se convierte en vapor al calentarse y en hielo al enfriarse.
• 💨 Al aumentar la temperatura de un gas, su presión también aumenta, lo que se demuestra al calentar un contenedor rígido y observar cómo sube la presión.
• ❄️ Al enfriar un gas, su presión disminuye, lo cual se puede ver cuando se enfría un contenedor con gas y se reduce la presión interna.
• 🌋 La transformación de la materia de un estado a otro es posible debido a cambios en la energía cinética de sus partículas a través de procesos de calentamiento y enfriamiento.
• 🚀 La liquefacción de gases como el metano mejora su capacidad de almacenamiento y transporte, ya que su volumen se reduce significativamente.
• 🔬 Los cristales son una forma de sólido altamente organizada donde los elementos químicos están ordenados en un patrón que se repite en tres dimensiones.
• 🔬 La observación de cristales como el cuarzo proporcionó una de las primeras pistas sobre la naturaleza de la materia sólida y la disposición de partículas en el estado sólido.
• 🌟 La comprensión de los estados de la materia y sus cambios es fundamental para procesos industriales, el almacenamiento de gases y la investigación científica en áreas como la cristalografía.

Q & A

¿Qué son los estados de la materia mencionados en el guion?

Los estados de la materia mencionados son sólido, líquido y gas.

¿Qué ocurre cuando la materia cambia de un estado a otro?

El cambio de estado ocurre por variaciones de temperatura o presión, lo que afecta el comportamiento de las partículas de la materia.

¿Qué relación hay entre la temperatura y el estado de la materia?

La temperatura afecta la energía cinética de las partículas; al aumentar la temperatura, las partículas se mueven más rápido y pueden cambiar de sólido a líquido o de líquido a gas.

¿Qué sucede cuando el gas se enfría significativamente?

Cuando un gas se enfría lo suficiente, las partículas pierden energía, se ralentizan y el gas se condensa en un líquido. Si se enfría más, el líquido se solidifica.

¿Qué demuestra el experimento con el balón de acero y el calentador?

El experimento muestra que cuando el gas en el balón de acero se calienta, su presión aumenta debido al incremento de la velocidad de las partículas. Cuando se enfría, la presión disminuye.

¿Cómo se explica el colapso de la lata en el experimento?

El colapso ocurre porque al enfriar el vapor dentro de la lata, se reduce la presión interna, lo que hace que la presión atmosférica externa aplaste la lata.

¿Qué es la licuefacción del gas natural y por qué es importante?

La licuefacción es el proceso de enfriar el gas natural a temperaturas extremadamente bajas para convertirlo en líquido. Es importante porque reduce su volumen y facilita su almacenamiento y transporte.

¿Cómo afectan los cambios de temperatura a las propiedades de los materiales, según el experimento con las pelotas de goma?

El enfriamiento extremo con nitrógeno líquido endureció las pelotas, volviéndolas frágiles. Al regresar a la temperatura ambiente, las pelotas recuperaron su flexibilidad.

¿Qué ocurre a nivel microscópico cuando un gas se convierte en líquido y luego en sólido?

Las partículas de gas, al enfriarse, pierden energía, se agrupan por fuerzas de atracción y forman un líquido. Al enfriarse aún más, estas partículas se ordenan en una estructura rígida, formando un sólido.

¿Qué se menciona sobre las estructuras de los cristales y su relevancia científica?

Los cristales tienen una estructura altamente ordenada que refleja la disposición precisa de los elementos químicos, proporcionando una visión única sobre la naturaleza de la materia en estado sólido.

Outlines

00:00

🌟 Estado de la Materia y Transformaciones

Este párrafo introduce el misterio de los tres estados de la materia: gas, líquido y sólido, y cómo estos pueden interconvertirse. Se explica que todo en nuestro mundo está en uno de estos estados y que la química comienza con esta idea fundamental. Se utiliza el Gran Salto del Río Potomac como ejemplo de cómo la roca, el agua y el aire están en diferentes estados de la materia. Se menciona que la temperatura es clave para entender estas transformaciones de estado.

05:00

🔥 El Efecto de la Temperatura y la Presión

Se explora cómo la temperatura afecta la presión y, por ende, el estado de la materia. Se realiza un experimento con un frasco de agua que se calienta hasta que el agua se transforma en vapor, aumentando la presión y causando que el frasco se hinche. Al disminuir la temperatura, el vapor se condensa en líquido y la presión disminuye, lo que hace que el frasco se encogue debido a la presión atmosférica externa. Se usa un aparato para demostrar la relación directa entre la temperatura y la presión de un gas: al aumentar la temperatura, aumenta la presión, y al disminuirla, disminuye la presión.

10:00

💧 Liquefaction de Gas y su Importancia

Se discute la importancia de la liquefaction de gases, como el metano o gas natural, para aumentar la capacidad de almacenamiento y facilitar el transporte. Se describe el proceso de liquefaction en tres pasos: enfriar el gas para congelar el vapor de agua, filtrar impurezas y enfriar aún más para convertir el gas en líquido. Se menciona que el almacenamiento de gas natural licuado (GNL) es mucho más eficiente que en su estado gaseoso y se puede transportar fácilmente. Además, se muestra cómo el nitrógeno líquido, a una temperatura extremadamente baja, puede cambiar las propiedades temporales de objetos como bolas de raquetas.

15:03

🌡 Cambios de Estado y su Impacto en la Vida Cotidiana

Se explica cómo los cambios de estado de la materia, particularmente la evaporación, afectan nuestra vida diaria, como cuando sudamos para enfriarnos. Se menciona que el proceso de evaporación requiere energía que se toma de nuestro cuerpo, lo que produce la sensación de frescura. Se introduce la idea de que estos cambios de estado tienen un origen en el comportamiento de partículas a nivel microscópico, como átomos y moléculas.

20:03

💠 Los Cristales y su Orden Microscópico

Se aborda la naturaleza altamente organizada de los cristales como una forma de sólido. Se describe cómo los cristales proporcionan una visión de cómo los átomos están organizados en la materia sólida, con arreglos repetitivos en tres dimensiones. Se destaca la belleza y la fuerza de los cristales, así como su importancia en la comprensión de la naturaleza de los elementos químicos. Se menciona la colección de cristales raros en el Museo Smithsonian y se concluye con la idea de que los cristales son una ventana a la organización de la materia.

25:04

🔬 La Naturaleza de la Materia y sus Estados

Se resume que la materia puede estar en tres estados: gas, líquido y sólido, y que los cambios de estado dependen del movimiento de partículas submicroscópicas. Se destaca que el enfriamiento disminuye el movimiento de las partículas y el calentamiento lo aumenta. Se menciona el uso de gases como el gas natural y cómo la liquefaction reduce su volumen para facilitar su almacenamiento y transporte. Finalmente, se sugiere que los cristales son una forma altamente ordenada de la materia sólida y se alude a la próxima exploración de la naturaleza de los átomos.

Keywords

💡Estados de la materia

Los estados de la materia son las formas en que la materia puede existir: sólido, líquido y gas. En el video, se explica que estos estados están definidos por la disposición y el comportamiento de las partículas submicroscópicas, y cómo pueden cambiar de un estado a otro mediante la variación de temperatura y presión, como cuando el agua cambia de sólido a líquido y luego a gas.

💡Temperatura

La temperatura es una medida de la energía cinética promedio de las partículas en una sustancia. En el video, se destaca que la temperatura es crucial para cambiar los estados de la materia, como cuando el aumento de temperatura convierte un líquido en gas. La demostración del recipiente con vapor y su posterior colapso al enfriarse ilustra cómo la temperatura afecta la presión de un gas.

💡Presión

La presión es la fuerza ejercida por las partículas de gas cuando chocan contra las paredes de su contenedor. En el video, se muestra cómo la presión de un gas aumenta con la temperatura debido a un mayor número de colisiones y una mayor fuerza de impacto, y cómo disminuye cuando se enfría, lo que provoca cambios en los estados de la materia, como el gas volviéndose líquido.

💡Energía cinética

La energía cinética es la energía que poseen las partículas debido a su movimiento. En el video, se explica que la velocidad y, por lo tanto, la energía cinética de las partículas de un gas aumentan con la temperatura, lo que a su vez afecta la presión y los cambios de estado. A menor energía cinética, como en temperaturas más bajas, las partículas se mueven más lentamente, facilitando la transición a estado líquido o sólido.

💡Condensación

La condensación es el proceso mediante el cual un gas se transforma en un líquido al perder energía térmica. En el video, se demuestra con el experimento del recipiente lleno de vapor: al enfriar el gas dentro del recipiente, este se condensa en agua líquida, reduciendo la presión interna y provocando que el recipiente se colapse debido a la presión externa del aire.

💡Liquefacción

La liquefacción es el proceso de convertir un gas en un líquido mediante enfriamiento y eliminación de impurezas. El video muestra cómo este proceso se utiliza industrialmente, como en la planta de gas natural licuado, donde el gas se enfría a temperaturas extremadamente bajas para reducir su volumen y facilitar su almacenamiento y transporte, destacando la importancia de controlar la temperatura en la manipulación de gases.

💡Cristales

Los cristales son sólidos con una estructura interna ordenada y repetitiva de partículas. En el video, se describe cómo los cristales son ejemplos de materia en estado sólido, donde las partículas están dispuestas en patrones regulares tridimensionales, lo que les da su forma y fuerza características. Se mencionan ejemplos como el cuarzo y otros minerales exhibidos en el museo Smithsonian.

💡Enfriamiento rápido

El enfriamiento rápido es el proceso de bajar rápidamente la temperatura de un objeto o sustancia, como se muestra en el video con el uso de nitrógeno líquido. Este proceso puede cambiar las propiedades de los materiales, como la demostración con las pelotas de raqueta que se vuelven frágiles y se rompen al golpearlas con un martillo después de ser sumergidas en nitrógeno líquido, ilustrando los efectos de temperaturas extremadamente bajas.

💡Fuerzas atractivas

Las fuerzas atractivas son las interacciones que mantienen unidas a las partículas de una sustancia. En el video, se explica que estas fuerzas son responsables de la formación de sólidos y líquidos a medida que las partículas pierden energía cinética y se acercan entre sí, superando la tendencia al movimiento desordenado, como se observa en la transición de gas a líquido y finalmente a sólido en la muestra de bromo.

💡Cambio de estado

El cambio de estado se refiere a la transformación de la materia de un estado a otro, como de sólido a líquido o de líquido a gas. En el video, se examinan estos cambios a través de experimentos y ejemplos prácticos, como la transformación del vapor en agua al enfriarse, y se discuten los factores subyacentes, como la temperatura y la presión, que facilitan estos procesos, resaltando la importancia de la energía en los cambios de estado.

Highlights

Everything in our world exists in one of three states: gas, liquid, or solid.

Matter can change from one state to another.

The transformation of matter's state begins with temperature.

Heating a liquid can change its state to a gas, as seen with heated water turning into steam.

As temperature decreases, the pressure inside a container also decreases, causing the can to cave in.

The relationship between temperature and pressure of a gas is direct: as temperature increases, so does pressure.

Sub-microscopic particles of a gas move faster and collide more frequently with container walls when heated.

Cooling a gas decreases its pressure, and can lead to a change of state to liquid.

Gaseous matter becomes liquid at low enough temperatures, which is crucial for storing gases like oxygen and carbon dioxide.

Liquefying natural gas increases storage capacity by over 600 times.

Liquid nitrogen at -196°C can be used for fast freezing processes without damaging materials.

The process of evaporation cools the skin when sweating by supplying heat from the body.

Bromine can be observed transitioning from gas to liquid to solid as temperature decreases.

Crystals are a highly ordered form of solid matter, providing insight into the arrangement of particles.

Crystals reveal the fundamental nature of solid matter and the behavior of chemical elements.

Matter's states are few, but the variety of substances realizing these states is vast.

The forces between atoms or molecules dictate the state of matter, such as gas for oxygen and solid for sulfur.

Transcripts

there is a mystery to this world around

us

an idea so obvious we take it for

granted but so important that all

chemistry starts from it

everything in our world exists in one of

three states

as a gas

[Music]

a liquid

or a solid but can change from one state

to another

how is this possible

what happens as a solid becomes a liquid

and a liquid a gas

in the world of chemistry it's all a

matter of state

[Music]

the great falls of the potomac river

near washington

everything in the scene around me

the rocks the flowing water the trees on

the other side even the air that i

breathe everything is matter it's

chemical

and even though we see hundreds of

different substances

millions where i to look with a

microscope

these substances fall into certain

groups or classes that we can identify

as gases

liquids and solids

these are the states of matter

gases are tenuous compressible

the space that matter fills we call that

volume is obviously occupied less

densely in gases than it is in the other

states of matter

liquids are fluid

deformable more dense than gases and

solids are more compact still often

denser and it's not only that the states

are there

we or nature can change them

why is a crystal like an iceberg

how is lava like a stream

what does a balloon have in common with

the air around it

the iceberg and the crystal are both in

the solid state

this lava and the water in the stream

are both in the liquid state

the matter inside this balloon and the

air around it are both in the gaseous

state

under certain conditions matter changes

state what makes this transformation

possible

water at one temperature is a liquid at

another temperature a gas at still

another

it is a solid

if we are to begin unraveling the secret

of matter's transformation temperature

is a clue

what is its effect on liquids and

gases let's start out by looking at the

effect temperature has on pressure what

i'm going to do

is heat this can

this is a rigid

can

has some water in the bottom up

now as the water is heated it will

change state

you're very familiar with the term steam

huh steam now is gaseous water

now as that steam is formed from that

liquid liquid to gas

it will drive out the air

that was inside that can and hopefully

we'll be able to see

some of the steam that is coming out of

the top of the can

once we have driven all the air out

what i'm going to do is put the top on

there

and we'll let the can cool

and see what happens

with the pressure

as the temperature decreases

what do you think do you think there's

enough

steam coming out there to indicate that

the all the air has been driven out all

right i'm gonna take the burner off turn

that off

we'll cap this up

all right now

as the temperature decreases

the can cools

that steam will change back into

liquid

as it does that

it will decrease the pressure inside the

can

oh you hear that

as the pressure decreases

what anything happen out here the

atmospheric pressure didn't change

it's pushing on the can just like it was

before

but since the pressure is less

as we decrease the temperature the

pressure decreases

the can starts to cave in

[Music]

there it goes

[Music]

now look at the can notice how the can

is

crushing

the reason now again is because of that

atmospheric pressure the gas of the

atmosphere

inside now the pressure was reduced

because the steam condensed

into that liquid leaving

a decreased pressure inside

the atmospheric pressure pushed in the

can

so heating a liquid can change its state

to a gas and there appears to be a

relationship between the pressure of

matter in the gaseous state and its

temperature

but what is the nature of this

relationship

we'll use this apparatus to try to

understand that relationship between the

temperature and the pressure of a gas

we have a rigid container here this is a

steel ball that's attached to this

pressure gauge

now because it's rigid the amount of gas

inside and the volume of the gas will

remain the same the only things will

vary are pressure and temperature

let's try it and see what happens

all right we'll heat it up using this

burner

so as we increase the temperature of the

gas inside the ball

what happens to the pressure

can you see that pressure what's

happening there

it's increasing isn't it the number is

getting higher

so as we increase the temperature of the

gas

we also increase the pressure

all right now what would happen if we

take the heat away and cool it well

let's see i'll take the burner away and

we'll turn off the gas

and we'll let it cool

well it's not cooling fast enough let me

help it

i've got this this ice water bath so i

stick the ice water bath up there

and we'll cool the ball

and look what happens now to the

pressure

as the temperature decreases the

pressure of a gas also decreases

so we see the relationship between the

temperature and the pressure of a gas

what is happening to the sub-microscopic

particles of a gas as they are heated

and cooled

how does this affect pressure

if we could slow down the gas particles

and focus on just a few of them they

would look like this

far apart moving randomly in straight

lines

when they collide with the walls of the

container they exert a pressure against

the walls

these moving particles possess kinetic

energy

their speed depends on their temperature

as the gas is heated and the particles

move faster

they collide with the walls of the

container more frequently

because they are moving at greater speed

they also strike the walls with greater

force

both effects the greater number of

collisions and the greater force of the

collisions contribute to the increase in

the pressure of the gas when the

temperature is increased

cooling a gas decreases the speed of the

particles

as the temperature is decreased the

kinetic energy of the particles

decreases

they slow down

they strike the walls less frequently

and with less force as we cool a gas

down to a certain point we continue to

decrease its pressure

but if we cool a gas beyond that point

something dramatic happens

the gas changes state to become a liquid

the fact that gaseous matter becomes

liquid matter at a low enough

temperature is important to us

every year we use billions of liters of

different gases

in hospitals pure oxygen helps very ill

patients breathe more easily in soft

drink factories another gas carbon

dioxide gives beverages their fizz

just plain air a mixture of mostly

nitrogen and oxygen is bottled under

high pressure for scuba divers to

breathe underwater

gases are also used in the manufacture

of integrated circuits

the processing of steel

the recovery of oil and many other

places

but the place we are probably most

familiar with is the home where we heat

and cook with a gas cold methane or

natural gas

and we would have a hard time using

natural gas if we couldn't liquefy it at

low enough temperatures

linwood basemore is chief of baltimore

gas and electric's liquid natural gas

facility the primary reason for

liquefying natural gas is

to

give us added storage capacity

capabilities of storing lng are much

greater as a liquid than as a gas

to demonstrate

methane liquefied is reduced in volume

over 600 times we we liquefy during the

summer when our system demands are low

that gas is made available then for

storage

and in the winter months when the demand

is high

we can supplement our supplies with our

own

lng

natural gas is converted to a liquid and

stored at plants like this throughout

the world

liquefaction is a three-step process

the gas comes in through pipelines in a

gaseous state but it contains impurities

like water vapor and carbon dioxide

so the first step is to cool the gas

enough to freeze out the water vapor

this is done in towers that are filled

with coils of a cold liquid similar to

antifreeze

as the natural gas passes over them

water vapor condenses and forms ice

the natural gas then goes to a filter

system that removes other impurities

now the gas is ready to be chilled to a

liquid

the liquefaction process simply

reduces molecular motion

that provides for the condensing of the

material

when we remove the sensible and latent

heat from the methane from 60 degrees

fahrenheit down to -260

molecular motion is essentially

slowed down

the red tanks in this plant contain

natural gas that is waiting to be

liquefied the white tanks contain

liquefied natural gas

the volume occupied by natural gas in

the liquid state is so reduced that one

white tank can hold 125

red tanks

we store lng in essentially what is is

just a large thermos bottle

the tanks are not refrigerated in any

way other than the auto refrigeration

supplied by the liquid within the tanks

the tanks are essentially a tank within

a tank they're

insulated

around a top and bottom

and there's no additional refrigeration

needed

one of the benefits of liquefying

natural gas is that it makes it

essentially portable

methane or natural gas in its natural

state as a gas

must be delivered via connected pipeline

from point a to point b

however in as a liquid

lng can be delivered via truck

rail or even

shipping another advantage of a

liquefied gas is its extremely low

temperature

how cold is it

in this container i have an element that

we're all familiar with but most the

time is a gas

nitrogen only this is liquid nitrogen

and here there's a couple racquetballs

notice how they balance very well

now what will happen to those balls as i

put it in that liquid nitrogen

now this liquid nitrogen is at a

temperature of minus

196 degrees celsius

so the temperature inside there now is

some

225 or so degrees below room temperature

so that ought to change the properties

of those balls that are inside there

quite a bit

well i think the balls have been there

long enough now let's see what happened

i'll put these gloves on because that

liquid nitrogen is very cold i don't

want to

burn my fingers

i'm going to take one ball out

and i'll set it right here and we'll let

that one alone

and i'll take the other one out

and just to show you what this liquid

nitrogen has done because it is so very

cold i'm going to take that ball and hit

it with this hammer

here we go

the ball shatters

so we see now that there has been a

tremendous change

in the properties of that particular

ball because of this low temperature

all right now here's the other bowl it's

warmed up now so i don't need that glove

anymore look

it's back to normal

so this fast freezing process even with

something as cold as liquid nitrogen

really doesn't harm the material it

certainly changes the properties

immediately like this spa that we

shattered but after a while when it

warms up it's back to normal

liquid nitrogen also has many practical

uses

we take fresh food at the grocery store

for granted its delivery depends on

trucks that use liquid nitrogen for

refrigeration cooling the food without

freezing it

other foods are packaged and flash

frozen using liquid nitrogen

and biochemical researchers continue to

develop cryogenic techniques for

freezing living tissue without damaging

it

this work will make it possible to store

whole organs for indefinite periods

we've seen now how matter can change

from a gas to liquid

in a process energy is emitted in a form

of heat that heat has to be taken away

and this is why we cool a gas in order

to liquefy it the reverse process is

that of heating a liquid in order to

make it go into the gaseous state

these energy changes are crucial

and they're also part of our everyday

experience

for instance we can understand now how

it is that we cool off when we sweat and

when someone puts a wet cloth on a brow

of a feverish person

what happens is that water liquid

evaporates goes to water gas

in order to accomplish that heat has to

be supplied to the liquid water

that heat must come from somewhere it

comes from my skin

that is why my skin feels cooled off

when i sweat

these energy changes that we have been

discussing

in the observable macroscopic world of

gases liquids and solids

must find their origin their causes

in the microscopic world of atoms and

molecules

let's take a look at one particular

substance as it moves through the three

states of matter

what you're looking at is a closed

container of bromine see the bromine

liquid here

red dark brown liquid and the bromine

gas filling the rest of the vessel a red

brown gas

i'm going to make use of this liquid

nitrogen again remember it's very cold

minus 196 degrees celsius

to lower

this vessel

so that the

finger end of that gets into the liquid

nitrogen

now what will happen at that temperature

is that bromine

should change

state

so the gas should go into the liquid

and the liquid should go into the solid

so we see all three phases all three

states of matter in action

all right let's wait a little bit and

see what happens now while that while

that flask

cools down

at this stage now we can see all three

states of matter

this is the bromine gas

top part up here the dark material now

is the bromine liquid

and at the very bottom is the yellow

solid of bromine

all three states of matter

we know that as we go from the gas

and decrease the temperature we go to a

liquid we decrease the temperature

further we go to the sun

on the sub-microscopic level the bromine

particles in the gaseous state are

moving quickly and chaotically

as the temperature decreases the

particles slow down until the attractive

forces between them overcome the

randomizing forces of kinetic energy

when these two forces reach a balance

the particles begin to stick together in

clumps

when the clumps become large enough

gravity pulls them down to the bottom of

the container

now the particles are in relatively

close contact attractive forces are

holding them together but they are still

moving

as the liquid becomes colder the

particles lose even more kinetic energy

this results in another change of state

the liquid becomes a solid

now the attractive forces hold the

particles in a regular and ordered form

that extends in three dimensions

crystals are one of the most beautiful

examples of this ordered arrangement of

particles

although they look like they were

fashioned with a sculptor's skill

these formations are completely natural

they come from one of the most extensive

collections of rare crystals in the

world housed in the vaults of the

smithsonian museum

many are too delicate for public display

what gives crystals their unique

appearance

dan appleman is a geologist at the

smithsonian

a crystal is a particular kind of matter

in which the chemical elements which

compose all kinds of matter are very

highly organized they're not just

organized but they're organized into a

very orderly array like a column of

soldiers an extremely ordered form of

matter is what we see when we look at a

crystal what this means is that

within a crystal the chemical elements

are arranged in a particular way to form

a building block you can think of a

building block as being like a like a

brick in a brick wall and these building

blocks within the crystal then are

stacked in a very regular arrangement in

three dimensions just like the bricks

are stacked in a wall

and in crystals unlike other forms of

matter you can sometimes see the shape

of these submicroscopic building blocks

with the naked eye

if the conditions are right the external

shape of the crystal is the same as the

shape of the particles that make it up

because of this

crystals provided one of the first clues

to the fundamental nature of solid

matter way back in the 16th century that

the

famous danish naturalist nils stenson

observed that

wherever a crystal of quartz such as

this was found

the angles between the faces were always

the same they weren't just random faces

they always had the same angles between

them and in fact quartz from anywhere in

the world from hot springs arkansas like

this huge slab or from brazil like these

beautiful amethysts

doesn't matter where the quartz comes

from what color it is what shape the

crystals are the angles between their

faces are always the same

infinitely repeating patterns of

chemical elements

the invisible world of fundamental

particles laid bare through the external

beauty of these shapes

in crystals we can also see how

particles in a solid are arranged to

create strength

this is different from other forms of

matter for example in a gas the chemical

elements are only very loosely and

weakly organized if at all and they have

very little relationship one to the

other which is why a gas can expand to

fill any volume that one wishes in a

liquid the chemical elements are a

little bit more organized there is an

attraction between the elements and so a

liquid has a volume to it but it will

flow

and fill any shape volume that you want

to pour it into because it does not have

any rigidity at all but it is more

organized than a gas a crystal is far

more organized than a liquid a crystal

has a rigid shape which will not change

because the

chemical elements that form the crystal

have a rigid arrangement with respect to

each other which does not deviate

strong and rigid but elegant and

fascinating crystals take many forms

from gemstones like the hope diamond the

largest blue diamond known in existence

to natural specimens of all shapes and

colors

crystals exert a grip upon both our

imagination and our scientific curiosity

i think the most fascinating thing about

crystals at least from the standpoint of

a scientist that wants to study matter

is the unique insight that a crystal

gives you into the nature of matter

itself into the way that chemical

elements behave toward each other

it's very hard to do this in a form of

matter such as a gas or a liquid where

the chemical elements don't really have

much to do with each other but in a

crystal the intimate association of the

elements tells you a lot about the

nature of the chemical elements

themselves just like an intimate

association between people will tell you

a lot about individuals and so i find

crystals especially fascinating because

they tell us so much about the nature of

the chemical elements themselves

to review

matter can occupy three different states

gas liquid and solid

changes of state depend on the motion of

submicroscopic particles the motion of

these particles depends on energy

cooling particles takes away energy and

slows them down

heating particles adds energy and speeds

them up

in a gas these particles move quickly

and randomly they have no set volume or

shape

in a liquid the particles slow down and

clump together

we use gases such as natural gas in many

important ways

cooling a gas into a liquid decreases

its volume dramatically this makes it

possible to store and transport it more

efficiently

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in a solid particles of matter have a

definite volume and shape they are held

in a pattern that repeats itself in

three dimensions

crystals are a highly ordered form of

solid matter

they were one of the first clues to the

arrangement of particles in the solid

state

the states of matter

are few

but the ways in which they are realized

the number of different substances

around us

are many

let me give you an example i'm breathing

oxygen the life giver

and that's obviously a gas

but here is another element sulfur

that's chemically very closely related

to oxygen

and yet it's obviously different it's a

solid at room temperature

now

there are obviously different forces at

work between the atoms or molecules of

sulfur and oxygen within these two

substances we want to know why that is

so we have to probe deeper we have to

then ask

what is the nature of the atom what is

it that makes an oxygen and a sulfur

similar or different

we will begin to look at this in the

next program

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so

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you