Notes on States of Matter

Notes on States of Matter

1. Solids –

·  Have a definite volume

·  Have a definite shape

·  Have a definite mass

·  Bonds that are very close together hold the atoms in s specific shape

2. Liquids –

·  have a definite volume

·  No definite shape; takes the shape of its container

·  Have a definite mass

·  Some of the bonds break apart and the substance loses its shape; will take the shape of its container

·  Atoms are close together but slide/move past each other

3. Gases

·  No definite shape

·  No definite volume

·  Definite mass

·  All bonds are broken and a gas will spread to fill whatever container you put it in

BONDS

Atoms are held together by invisible bonds

·  a bond is an invisible force that attracts atoms to each other

·  It is NOT gravity or magnetism, but it works in a similar fashion

What causes things to change state?...that is to boil or melt

·  In a solid, an object keeps its shape because the atoms are held in place by invisible bonds – think of invisible rubber bands

·  As you add energy, the atoms move faster and bounce off each other and get farther apart

·  When the atoms get too far apart, some of the bonds stretch and break. Then the solid loses its shape and becomes a liquid

Do Liquids have bonds? Yes.

·  BUT…if you keep adding energy, eventually all the bonds break, and now it’s every atom for itself

·  When a solid turns to a liquid we have MELTING ( melting is called fusion)

·  When a liquid turns to a gas, we have VAPORIATION or BOILING (vaporization is boiling)

NOTE: Every material has a specific melting and boiling point

Malting and Boiling points are characteristic properties

Characteristic Property – a property that is specific for a substance and does not change when

the amount of the substance changes

Changes in Matter

·  In a solid the atoms are held together by an invisible force called a BOND – ( it is NOT gravity or magnetism, but it works in a similar fashion

·  As you add energy, the atoms move faster and start spreading farther apart

·  As you remove energy, the atoms move slower and start getting closer together.

·  CONDENSATION – a change from a gas to a liquid (gas particles start to cool and move closer together

·  EVAPORATION – occurs when a substance changes for a liquid to a gas WITHOUT reaching the boiling point

·  HEAT of FUSION – (HF) the energy needed to break the bond in a solid and change it into a liquid

·  Heat of Fusion is an actual Number but is different for different substances. For Ice at 0 degrees Celsius you would need 80 calories to melt each gram of ice

·  HEAT OF VAPORIZATION – (HV) the energy needed to break the bond in a liquid and change it to a gas

·  Heat of vaporization is also an actual number and for ice it is 540 calories per gram

·  Remember! Boiling and vaporization are the same thing AND melting and fusion are the same thing

·  Melting Point – the temperature at which a solid turns into a liquid

·  Boiling Point – the temperature at which a liquid turns into a gas

·  SUBLIMATION- this occurs when a solid turns directly to a gas (skipping the liquid state) as in our demonstration in class using dry ice

·  PLASMA – Plasma is a gas made of electrons and ions. Normally atoms have a positive center and a negative covering. When gases turn into plasma they become so hot and move so fast that atoms start to be torn apart. They become unorganized and they glow.

·  PLASMA -are made of ionized gases

·  PLASMA can be found in fluorescent light and the sun

·  BOSE-EINSTEIN CONDENSATE - (BEC – the 5th state of matter ) the name of 2 scientists – Einstein and Bose

When atoms are cooled to almost absolute zero ( and atoms slow down to an almost stop) a group

of atoms come together to form one super atom which is frictionless and highly conductive

Atoms loose their individual properties of matter at absolute zero

REVIEW!

Plank’s Temperature – the hottest temperature possible

Absolute Zero – the coldest temperature possible

NOTE – We have never reached Plank’s Temperature or Absolute Zero

FIVE STATES OF MATTER – Bose-Einstein Concentrate, Solid, Liquid, Gas, Plasma,

·  Bose-Einstein Concentrate – atoms are cooled to almost absolute zero and are barely moving

·  Solid – atoms have some energy and are moving slowly and are very close together

·  Liquid – atoms have a bit more energy and are moving a little faster and move a little farther apart

·  Gas – atoms have much more energy and are moving much faster and move even farther apart

·  Plasma – atoms have become so hot and moving so fast that they become torn apart and glow

HOW DO THINGS CONDENSE OR FREEZE?

·  In a gas, atoms are flying all over, separated from each other, with no bonds to break them

·  AS you remove energy, the atoms move slower, and start getting closer together

·  When the get close enough, SOME OF THE BONDS COME BACK

·  SOME of the atoms begin to clump together, and you get drops of liquid forming out of the gas

·  Eventually, all of the gas turns into a liquid

·  If we continue to remove energy, the atoms will get even slower, more bonds form and all of the atoms become “frozen” into a rigid shape

Melting Point Boiling Point

Water

Gallium 29.7646 Celsius, 2204 Celsius, 3999 F

Gold 1064.18 C, 1947.52 F 2856 C, 5173 F

Oxygen -218.4 C, -361.12 F -183.0C, -297.4 F