Chemistry chapter 3 Flashcards
What is a physical change
No new substances are made
Atoms and molecules within do not change
Are easily reversible
What is a chemical change
New substances are made
Are difficult to reverse
Name 3 things that increase the rate of diffusion
Temperature
Concentration
Particle size
What is thermal expansion
When particles in a solid or liquid gain enough energy to occupy more space
What is concentration
The number of particles packed in a certain volume
What is pressure
The average force on a certain area
What is density
The amount of mass per unit volume of a substance
What is the formula for density
DENSITY=mass/volume
Why is ice less dense than water
As it is arranged in a regular lattice and have gaps in between
What is the structure of metals
A lattice of positive ions
A sea of delocalised electrons
Why do metals conduct electricity
Because they have a sea of delicalised electrons
Why are alloys stronger than metals
Alloys are stronger because the Atoms are different sizes which makes the layers distorted
Name 3 General properties of solids
Cannot be compressed
Fixed shape
Fixed volume
Name 3 General properties of liquids
Compressible
Fixed volume
No fixed shape
Particles can slide over each other
Name 3 General properties of gasses
Particles move randomly
Lots of space between them
Invisible to the eye
Why does adding salt to water make it more dense
Because there is more mass in the same volume
What is viscosity
The ability to flow
What is compression
The ability to be squashed or pushed together there is more space between particles so they can be compressed
What is solubility
The ability to dissolve
Name some properties of metals
High melting point
Hard
Strong
Malleable
Ductile
Conductors
Who invented brownian motion
Robert brown
What is brownian motion
The random movement of particles in a fluid
What is latent heat
The heat required to change state without an increase of temperature
What is the state change from solid to gass called
Sublimation
