Changes Of State Flashcards
What happens when a solid or liquid is heated
The particles gain energy, vibrate faster until they have enough energy to overcome the forces of attraction between the particles and molecules to break free.
What happens when a gas or liquid is cooled
The particles loose energy and start to move and vibrate slower until they can’t overcome the forces of attraction and move closer together (liquid) or get stuck in a fixed position (solid)
What is equal to what at the boiling point
Atmospheric pressure=vapor pressure
Where does boiling occur
Throughout the liquid but only at boiling point.
Where does evaporation take place and what is it?
It takes place at the surface of a liquid and it is the removal of energy
When does evaporation take place
When the particles near the surface have enough energy to overcome the forces holding the liquid molecules together and they move into the space above the liquid.
When does condensation take place
When a gas is cooled to its boiling point and below
What is the boiling and melting/freezing point of water
100
0
MELTING + FREEZING POINT=THE SAME
Iron
2860
1538
Gold
2856
1063
Mercury
357
-39
Platinum
3825
1768
Oxygen
- 183
- 225
Hydrogen
- 253
- 260
What is sublimation
Solid to gas without going through the liquid stage eg. Dry ice sublimes+solid iodine
What is the change of state from gas to solid and eg.
Deposition
Frost
True false some substances have the same melting point/boiling point
False
All are unique
How can a scientist find out a substances purity
By finding its melting/freezing/boiling points
They can compare it to known points
If it melts over a range=impure
Or at different temp.
What is the Brownian motion
The random movement of particles suspended in a fluid (liquid or gas) from colliding with fast moving molecules/atoms in gas/liquid.
What is the Brownian motion named after and how did he discover it
Robert brown
By looking at pollen grains (in 1827) randomly moving in mater. He could not explain
How and who explained the Brownian motion
Albert Einstein ion 1905, the grains were being moved by individual water molecules.
What is diffusion
The movement and mixing of particles from areas of higher concentration to lower concentration.
What is an equilibrium
The state in which opposing forces are balanced.
What is volatile
Easily evaporated, unpredictable, changes rapidly
1 degree Celsius = to what kelvin
273,15
Si unit for density
Kg/m3
What is active transport
Movement of molecules/ cells from areas of lower concentration to higher.
What is osmosis
Osmosis is the scientific process of transferring fluid between molecules.
High to low
