Phase Changes
Liquid to solid is...
a) freezing
b) evaporation
c) sublimation
a) Freezing
What is the melting point of water?
0 degrees Celsius and above
Are particles always moving?
Yes....
Bonus: They do not move at absolute zero (0 Kelvin)
Forces that pull particles apart or keep them together are called Intermolecular forces
True or false
attractive forces are stronger pull together
replusive forces are weaker and move apart
True
Repulsive Forces - Magnets repelling each other
Attractive Forces - Magnet sticks to the whiteboard
What is matter?
Matter is everything that has mass and takes up space.
Gas to liquid is...
a) evaporation
b) deposition
c) condensation
Condensation
What is the freezing point of water?
Below 0 degrees Celsius
Show me what liquid particles look like (arrangement and movement)
You should be casually floating around but staying kind of close together
Cooling causes the attractive forces to :
a) strengthen and push together (contract) and take up less space
b) weaken and pull apart (expand) and take up more space
a) strengthen and push together (contract) and take up less space
What happens to mass during a phase change?
a) it changes
b) it stays the same
Double points if you say what this is called (hint C.O.M.)
b) It stays the same! This is known as conservation of mass!
A solid changing to a liquid is...
a) freezing
b) melting
c) sublimation
Melting
What is the boiling point of water?
100 degrees Celcius
Particles that are vibrating and huddled tight together are...
Solids!
Heat causes the intermolecular forces in matter to:
a) weaken and pull apart
b) get stronger and push together
a) weaken and pull apart
What happens to volume during a phase change?
a) it changes
b) it stays the same
a) Volume will also change!
Think about how a frozen water bottle is a lot bigger than a bottle of water
A liquid going to a gas is called....
a) condensation
b) vaporization
c) deposition
Evaporation or vaporization
Explain how applying cool temperatures affects particle movement.
Particles will begin to slow down and get closer together.
(think about how people walking in a blizzard sometimes freeze to death because they slow down)
Particles going through condensation:
a) move more and spread out
b) move less and closer together
b) move less and closer together
What is the liquid called that is found in a thermometer?
Heating is what causes this liquid to expand and move up.
alcohol or mercury
When heat causes particles to move and take up more space it is called:
a) thermal expansion
b) thermal contraction
a) thermal expansion
What is deposition?
A gas changing directly into a solid without going through the liquid state
Explain how cold and hot weather can affect infrastructure (buildings) using your knowledge of particle movement.
It can causes cracks in the pavement and weaken the strength of buildings and bridges
Particles going through sublimation:
a) start out close and vibrating and then move super fast and far apart
b) start out far apart and then move super fast to get closer together
a) start out close and vibrating and then move super fast and far apart
Explain the strength of intermolecular forces when particles are heated and cooled.
When particles are heated, energy is being added, and this weakens the intermolecular forces. This is why particles get farther apart as they get heated.
When particles are being cooled, they get closer together because the intermolecular forces are getting stronger!
Heat is needed in order for which phases to occur:
a) evaporation and condensation
b) sublimation and deposition
c) evaporation and melting
c) evaporation and melting