Changes in states of matter pt.1

Change of state, AKA phase change A change from one state of matter to another is a result of two things Changes in the motion of the particles Strength of the forces between the particles

Temperature Temperature is a measure of the average kinetic energy of the particles in a material Kinetic energy of an object increases as its speed increases Temperature of a substances increases as the particles move faster and have more kinetic energy Hot air vs. cold air, circulating air

Thermal energy Thermal energy includes both kinetic energy and potential energy Different states of matter have different amounts of thermal energy Gas particles move faster and farther apart then solids For any substance, the particles have most thermal energy in the gas state and the least amount in the solid state

Adding and removing thermal energy Adding thermal energy to a substance can cause either an increase in temperature or a change in state A change in state is when matter changes from one state to another Solid to liquid, liquid to solid Liquid to gas, gas to liquid Gas to solid, solid to gas

Changes of state pt.2 review of states of matter

Melting Solid to a liquid Heat a solid up, thermal energy flows into the solid until it reaches melting point Melting point is the temperature at which the material changes from a solid to a liquid Every substance has a unique melting point Energy must be added to change from a solid to a liquid Melting is an endothermic change (absorbs heat)

Freezing Liquid changes into a solid Material cools, thermal energy flows out of the material Freezing point is the temperature at which the liquid changes into a solid Opposite of melting, exothermic reaction (releases heat)

Vaporization (boiling) Liquid to a gas (vaporization) For water, 100 degrees Celsius is boiling point, when it starts to evaporate When vaporization occurs, attractive forces between particles become too weak to keep particles close to each. They spread out and move independently Evaporations occurs at the surface of a liquid

Condensation Gas to a liquid Large number of atoms /molecules clump together On a hot day you might see drops of water on the outside of a glass of ice cold water Dew in the morning is another example Reverse of vaporization, exothermic reaction (releases energy)

Sublimation and deposition Solid to a gas is sublimation, without going to liquid state Dry ice is an example Thermal energy must be added to a solid Gas to solid is deposition A form of crystallization Frost that forms on a leaf is an example

Diffusion Diffusion is the net movement of particles from an area of high concentration to an area low concentration Can occur with the states of matter, either by themselves or when mixing Diffusion video