1. States of Matter

• Solid • Liquid • Gas

• Regular Arrangement • Vibrate about a fixed position • Particles are very close together

• Randomly Arranged • Can flow and move around each other • Particles are close together and still touch

• Randomly Arranged • Move quickly in all directions • Particles are far apart

• Melting is when a solid changes into a liquid • Heat / thermal energy absorbed by the particles is transformed into kinetic energy • This causes the particles to vibrate more and start to move / flow • Melting happens at a specific temperature, known as the melting point (m.p.)

• Boiling and evaporation are both when a liquid changes into a gas • In boiling, heat / thermal energy causes bubbles of gas to form inside the liquid, allowing for liquid particles to escape from the surface and within the liquid • Boiling happens at a specific temperature, known as the boiling point (b.p.)

• Freezing is when a liquid changes into a solid • This is the reverse of melting and occurs at the same temperature as melting • So, the melting point and freezing point of a pure substance are the same • Freezing needs a significant decrease in temperature (or loss of thermal energy) and occurs at a specific temperature

• Condensation occurs when a gas changes into a liquid on cooling and takes place over a range of temperatures • When a gas is cooled its particles lose energy and when they bump into each other they lack the energy to bounce away again, instead, they group together to form a liquid

• Evaporation occurs over a range of temperatures • It can happen at temperatures below the boiling point of the liquid • Evaporation occurs only at the surface of liquids where high energy particles can escape from the liquid’s surface at low temperatures • The larger the surface area and the warmer the liquid surface, the more quickly a liquid can evaporate

The liquid in which a solute dissolves

The substance which dissolves in a liquid to form a solution

The mixture formed when a solute is dissolved in a solvent

A solution with the maximum concentration of solute dissolved in the solvent

Describes a substance that will dissolve

Describes a substance that will not dissolve

g per 100 g of solvent

• As temperature increases, solids usually become more soluble and gases become less soluble. • As pressure increases, gases become more soluble