1. states of matter

igcse

particle theory

-moving all the time

-different substances=different sizes

-attract each other

-all matter is made up of particles

-spaces between particles

3 types of particles

atom, molecule, ion

solid: properties

fixed shape, fixed volume, not compressible, cannot be poured

liquid: properties

no fixed shape, fixed volume, not compressible, can be poured

gas: properties

no fixed shape, no fixed volume, compressible, can be poured

solid: arrangement and movement

tightly packed/touching, regular pattern/lattice, vibrating on spot

liquid: arrangement and movement

close together/touching, randomly arranged, slide over one another/random

gas: arrangement and movement

spread apart, randomly arranged, move freely at high speeds/random

melting

solid to liquid

boiling

liquid to gas

sublimation

solid to gas

condensation

gas to liquid

freezing

liquid to solid

deposition

gas to solid

heating curve

solid→liquid→gas

cooling curve

gas→liquid→solid

effect of heat to particles in container

particles gain kinetic energy→move faster→collide with the walls more→bounce off each other and the wall→gain more force→increase gas pressure

effects of temp on volume of gas (at constant pressure)

temp increases→volume increases

tem decreases→volumeeff decreases

effects of pressure on volume of gas (at constant temp)

pressure increases→volume decreases

pressure decreases→volume increases

diffusion

net movement of particles from high concentration to low concentration (liquid and gas only)

particles in diffusion

spread out and mix by colliding with other particles, bouncing off in all directions

factors affecting rate of diffusion

temperature: increase temp→increase diffusion rate

mass of particles: lighter the particles→increase diffusion rate

element

pure substance made of only one type of atom that cannot be broken down into anything simpler by chemical methods

compound

pure substance made of two ore more elements held together by a chemical bond

mixture

two ore more different substances that are not chemically combined together

how to tell if a substance is pure

substance melts and boils at definite temperature

physical properties

properties that can be determined without the substance changing into another substance

physical properties examples

malleability, hardness, appearance, boiling/melting point, ductility etc

chemical properties

chemical reactions of the substance and the respective conditions under which the each reaction takes place

physical change

change in which no new substances are formed (e.g. cutting a piece of paper)

chemical change

change in which one or more new substances are formed (e.g. burning a piece of paper)