Solids, Liquids and Gases
- Created by: theninjaemu
- Created on: 23-04-17 16:18
View mindmap
- Solids, Liquids and Gases
- The kinetic model
- Describes how all substances are made up of atoms or molecules, which are arranged differently depending on the phase of the substance
- Solids
- Regularly arranged in a 3D structure
- Strong electrostatic forces of attraction holding atoms in a fixed position
- Atoms can vibrate, and so have kinetic energy
- Liquids
- Atoms have more kinetic energy than in solids
- Atoms are still very close together, but can change position and flow past eachother
- Gases
- Atoms have more kinetic energy than in liquids and are much further apart
- There are negligible electrostatic forces between atoms, unless they collide
- Atoms move randomly with different speeds and directions
- Density
- Spacing between particles in a substance in different phases affects its density
- Generally, a substance is more dense when solid and less dense when a gas
- Water freezes into a crystalline pattern held together by strong electrostatic forces
- In this pattern the atoms are slightly more spaced apart than in a liquid, so ice is less dense than liquid water
- Brownian motion
- Robert Brown (1827) observed pollen grains moving randomly on the surface of water
- Einstein explained the movement was due to collisions between the pollen and water molecules
- These collisions are elastic
- Transfer of momentum from water molecules to pollen grains caused the grains to move randomly
- This demonstrated that matter is made up of molecules that have kinetic energy
- The kinetic model
Comments
No comments have yet been made