1.what are the differences between solids, liquids and gases? 2.what are phase changes? today in...
TRANSCRIPT
1.WHAT ARE THE DIFFERENCES BETWEEN SOLIDS, LIQUIDS AND GASES?
2.What are Phase changes?
TODAY IN PHYSICAL SCIENCE
The KINETIC THEORY OF MATTER states that all matter is made of particles called atoms and that the atoms are in constant *motion. ( *They are vibrating.)
•Heat particles up and they vibrate faster.
•Cool particles down and they vibrate slower.
When heat is absorbed the particles move faster. When heat is given up the particles move slower.
•As particles move faster the temperature is increasing.
•As particles move slower the temperature is decreasing.
Temperature increasing Temperature decreasing
So… The speed at which atoms or molecules vibrate is proportional to their temperature!
You need to reeeeemember this!
Le Graph!
Pssst…speed is also related to Kinetic energy!
TEMPERATURE is a measure of the average kinetic energy of the “particles” ( atoms or molecules).
So…WHAT IS TEMPERATURE?
Temperature is NOT heat.
HEAT is a form of energy… temperature is a man made concept that explains the average motion of the atoms or molecules…
100deg Celsius
( the boiling temperature of water.)
0 deg. Celsius
Water freezes…
or ice melts
-273.15 deg Celsius
“Absolute ZERO”
ALL ATOMIC MOTION
STOPS !
•The real difference between solids, liquids, gases, and plasmas, is the
heat energy of the particles.
•Heat makes particles (atoms and molecules) move faster.
Solids
The particles of solids are closely packed together.
The particles of solids are constantly vibrating but they do not slip past one another.
Because the particles can’t slip past one another, a solid cannot be poured, and a solid has a definite shape.
LOWEST ENERGY of the four phases of matter
Liquids –
particles ( atoms or molecules) have more energy than solids.
Particles can slide past each other so the liquid takes the shape of the container.
Particles of a liquid have a definite volume.
Particles of a liquid can “flow”
Gases
Particles in Gases have more energy ( greater motion) than solids or liquids.
The particles in a gas will expand to fill the shape and volume of any container!
The particles in a gas move in straight line random paths. They bump into each other and the sides of the container.
PLASMAS
Particles in PLASMAS have more energy ( greater motion) than solids, liquids, or gases…AND…
…The hot gas
particles in a PLASMA have an electric charge.
Click here to see a short video on the differences between solids, liquids, and gases.
This is a phase change graph. It shows ice being heated, melted, and finally water heating and boiling to form a vapor.
Along line “A” the ice is heating, the particles are moving faster and faster as heat is added. The temperature & kinetic energy of the particles is increasing.
At point “E” the ice starts to melt. Line “B” shows that the temperature (and kinetic energy) of the molecules will remain constant until all the ice is melted.
Line “C” is showing that the water is heating up. The molecules are vibrating faster and faster as they gain heat. The temperature and KE are increasing.
Point “F” is the boiling point. Line “D” indicates that the temperature of the liquid remains constant as it boils.
The temperature (KE) doesn’t change.
The KE is constant.
Heat gained or given up changes only the distance between the particles (PE), not the speed. (KE)
The opposite happens when heat is removed… like when water is put into a freezer…
condensing
Freezing ( crystallizing)
cooling
cooling