States of Matter Changes all around us

What is Matter? Matter is anything that has mass (atoms) and volume (takes up space). EVERYTHING is made of matter.

3 States of Matter

Water in all 3 states

4 States of Matter There are four states of matter: Solid Liquid Gas Plasma

What Makes Something a Solid? Solids: Retain their shape, Molecules are close together, with strong force between molecules that holds the shape, Molecules moving very slowly (vibrating)

Solids

What Makes Something a Liquid? Liquids: Take the shape of its container, Molecules close but not as tightly held as in solids, Molecules move around each other. Liquids can have different viscosities

What is Viscosity? Viscosity = a liquids resistance to changing its shape. Thicker = higher viscosity Thinner = lower viscosity

What is a Gas? Gas: takes the shape of its container, molecules are very far apart and moving fast.

Some Gas

More Gas

Lots and Lots of Gas

Everything is in Motion All molecules are in motion

Everything has Heat All molecules have heat.

What is Heat? Heat is a transfer of energy

WHAT IS HEAT? Heat is: a transfer of thermal energy Thermal energy is the energy of the molecules of a substance Heat always goes from the warmer substance to the colder substance

Where Does Heat Come From? Sun, burning fuel, friction

How Does Heat Move? From HOT to COLD

Convection Convection = a substance in motion carries heat energy with it. (requires matter)

Conduction Conduction = is the molecule to molecule transfer of heat energy. (requires matter)

Radiation Radiation = photons travel through space from emitter to another point (does not require matter)

How Do We Measure Heat? Thermometer – measures the average Kinetic energy of the molecules in a substance. Celsius = water freezes at 0oC and boils at 100oC Farenheit = water freezes at 32oF and boils at 212oF. Kelvin = begins at Absolute Zero = -275 celsius = limit of coldness = the lowest possible kinetic energy that molecules can have (Theoretic point)

What is Absolute Zero? Absolute Zero = the temperature at which kinetic energy of molecules is zero, there is NO movement of the molecules.

The Kinetic Molecular Theory Kinetic Molecular Theory – explains thermal energy as the random movement of atoms or molecules; explains the properties of matter. All matter is made of atoms (molecules) The molecules are in constant motion (kinetic) Motion and spacing of the molecules determines the state of matter Temperature of the molecules determines the motion and thereby the state of matter. More heat = more motion = more space

Molecular Spacing and Heat Determine State of Matter or Phase Solid = close molecules, slow, “cold” Liquid = pretty close, faster, “warm” Gas = far apart, fast, “hot”

Phase Changes – Evaporation and Boiling Liquid + heat  Gas (Evaporation) ex. Puddle disappearing on a hot day (Boiling) Boiling = pressure of escaping water vapor = air pressure

Evaporation is a Cooling Process

Phase Changes - Melting Solid + heat  Liquid (Melting) ex. Ice melting to water

Phase Changes - Condensation Gas – heat  Liquid (Condensation) ex. Liquid forming on the outside of a cold glass

Phase Changes - Freezing Liquid – heat  Solid (Freezing) ex. Water cooling and changing into ice

Phase Changes - Sublimation Solid + heat  Gas (Sublimation) ex. Dry ice, moth balls disappear over time

Phase Changes - Deposition Gas – heat  Solid (Deposition) ex. Snow, frost on windows, breath on cold day, frost in freezer

Thermal Expansion Thermal Expansion = the expansion that occurs as a substance is heated

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