Post on 30-Jun-2015
Unit 3
Physical Properties of Matter
Physical Properties
• States of Matter• Melting point• Boiling point• Density • Viscosity• Conductivity• Malleability• Hardness
States of MatterThere are 4 states of matter
Solid- molecules move very slowly and are connectedtogether in a rigid formation, like crystals
Liquid- molecules move quicker and flow over each other in a fluid manner like sand grains flowing over each other. But, they remain attached and can not disburse upward.
Gases- molecules move very quickly, spread out, and have no connection to each other.
Plasma- Highly energized particles that begin emittingenergy. Florescent lights, Neon lights, and fire have plasma inside. The Sun is nearly all Plasma
Changes in the States of Matter• Solid to Liquid = Melting• a. Particles get more energy and begin rotating around
each other.
• b. There isn’t enough energy to break the inter-particular attractions, so the particles remain close (liquid).
• c. The energy required to break the crystalline connects to melt a solid is called the
Heat of Fusion
Water Ice melts at 32°F
Gallium melts at 86°F. So, it melts in your hand.
Changes in the States of Matter• Liquid to Solid = Freezing• a. Particles lose energy and slow down.
• b. Attractive forces between particles become stronger than the particles’ motion, so the particles begin merely vibrating in place.
• c. The amount of heat the particles lose to the environment turn into a solid is called the
Heat of Fusion
Liquid water freezes at 32°F.
Molten lava freezes at 1000°F.
Changes in the States of Matter• Liquid to Gas = Vaporization• a. Types:• 1) Boiling - rapid; gas bubbles are produced
throughout.• 2) Evaporation - slow; occurs at the surface.• b. Liquid particles gain enough kinetic energy to
overcome forces between the particles and they begin translational motion; this energy is called the heat of vaporization.Water boils at 212°F. But, water can evaporate at any temperature.
Changes in the States of Matter• Liquid to Gas = Evaporation• Evaporation is a cooling process.
• a. Particles in a liquid gain energy.
• b. They leave as gas particles (taking the energy with them).
• c. This leaves less energy in the liquid, therefore cooling down what is left.
•
Changes in the States of Matter• Gas to Liquid = Condensation• a. Particles lose energy, slow down, and come closer together.
• b. Forces between the particles become strong enough to make particles merely rotate around each other.
• c. The energy they lose as they become liquid is the
heat of vaporization.
Changes in the States of Matter• Solid to Gas = Sublimation• Dry ice - carbon dioxide• b. Iodine• c. Frost
The “smoke” you see is actually water vapor condensing to liquid because of the
cold temperatures of the CO2 gas!
Changes in the States of Matter• Gas to Solid = Deposition• Dry ice - carbon dioxide• b. Snowflakes• c. Frost
On Mars it can snow with no clouds
Changes in the States of Matter• Triple Point
Venus
Earth
Mars
Gas
Liquid
Solid
Plasma• The “4th” state of matter• Plasma are gases that are heated so high that
their electrons to be removed easily.• Atoms can be positive or negatively charged
and react to magnetic fields.• The Sun is made of plasma that is made of
hydrogen and helium.• Lightening is a plasma formed by hail stripping
electrons from water molecules.• Fluorescent lamps are plasma
ViscosityA Property of Liquids
Pitch has a viscosity 230 billion times higher than water.
This pitch drop started in 1927!
Honey has a medium viscosity
Water has low viscosity and flows easily
MalleabilityA Property of Solids
• Very malleable metal wiring• Gold is the most malleable of all metals• Some metals are brittle and fracture easily
Elements Can Be:Metals, Metalloids, and Non-Metals
Silicon is a metalloid
Phosphorus and Bromine are non-metals
Titanium is a metal
Conductivity• The ability to conduct electricity or heat.• Gold and silver are the best conductors. Since gold is very
expensive, it is only used for very specialized electronics.• Copper is usually used around the home and electronics. But, it is
also too expensive for transmission lines, so aluminum is used.• This means a lot of electricity is lost as heat on the way,. But, it is
cheaper and lighter for use.
Density• Density is the mass/volume• Substances will separate by their density with
heaviest at the bottom and lightest on top.• Salt water is denser than freshwater. So, where they meet is the halocline, with salt water at the
bottom and freshwater on top.