C1 Flashcards
Particle
A small piece of matter
Particle model
A model used to help us understand the makeup of a substance
Can also explain why some properties of a substance depends on its state
Particle model of a solid
Arrangement of particles: regular
Relative distance between particles: very close
Movement of particles: vibrate about fixed positions
Particle model of a liquid
Arrangement of particle: random
Relative distance between particles: close
Movement of particles: move around each other
Particle model of a gas
Arrangement: random
Relative distance between particles: far apart
Movement of particles: move quickly in all directions
Limitations of the particle model
The forces between particles aren’t shown
The size of particles isn’t shown
The space between particles isn’t shown
BTW
Electrostatic forces are strongest in solids, then liquids, then gases
Helium atom diameter = 6.2x10^-11
Gas -> Solid = deposition
Solid -> gas = sublimation
ratio of distance to diameter = distance between atoms/diameter of atom
Physical reaction
Particles are rearranged
Now new substances are made
Easy to reverse
E.g dissolving sugar, melting ice
Chemical reaction
Bonds are broken and remade
New substances are made
Very hard to reverse
E.g steel rusting, acid reacting with an alkali, cooking eggs
Atom
The smallest particle of an element that still has its chemical properties
Bond length
The distance between the centres of two joined atoms
Subatomic particle | relative mass | relative charge
Proton | 1 | +1
Neutron | 1 | 0
Electron | 0.0005 | -1
Molecule
Two or more atoms bonded together
Isotope
A version of an element with a different number of neutrons
Ion
A charged particle formed when atoms lose or gain electrons
