Matter and Atomic Structure Section 3.3- State of Matter Chapter 3 Matter and Atomic Structure Section 3.3- State of Matter

Solids – form crystals Substances with densely packed particles which may be ions, atoms, or molecules. Definite shape and definite volume. Crystalline structure= geometric patterns Crystals form symmetrical solid objects

Vocabulary Crystalline Structure Table salt crystals = cubic Vanadium crystals = hexagonal

Glasses Window glass Molten material chills very rapidly; atoms don’t have enough time to arrange in patterns. Made of disordered silicon and oxygen SiO2

Liquids Particles slide pass each other Do not have a definite shape, take the shape of a container. Have definite volume

Gases Particles move at very high speeds Evaporation – change of a liquid to a gas Sublimation – slow change of state from a solid, ice crystals, to a gas, water vapor, without and intermediate liquid state. No definite shape No definite volume

Plasma Plasma – hot, highly ionized, electrically conducting gases Matter is heated- 5000co Collisions are violent; electrons are knocked off As a result= positive ions + free electrons Example- Stars, lightning, neon sign

Changes of State Solids melt when they absorb thermal energy Liquids absorbs thermal energy, it evaporates Gas cools, it releases thermal energy in process called condensation (change from gas to a liquid)

First Law of Thermodynamics Matter cannot be created or destroyed. Law of conservation of matter Energy cannot be created or destroyed Law of conservation of energy Matter and Energy can only change from 1 form to another.