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