properties of matter chapter 2 – physical science
TRANSCRIPT
Properties of MatterProperties of MatterChapter 2 – Physical Science
Kinetic TheoryKinetic Theory
All matter is made of atoms and molecules that act like tiny particles
These particles are always in motion. The higher the temperature, the faster they move
At the same temp., more massive particles move slower than less massive particles
States of MatterStates of Matter
Solid = definite volume, definite shape
Liquid = definite volume, no definite shape
Gas = no definite volume, no definite shape
Plasma = gas-like, no definiteshape or volume
SolidsSolids
Have a rigid structure
Particles have almost no freedom to change position, low KE
Still vibrate around a fixed location
LiquidsLiquids
Take the shape of their container
Particles are held close together, but not attracted as strongly as particles in a solid, higher KE
Classified as a fluid because it can flow
GasesGases
Free to spread in all directions
Under standard conditions, gas particles move rapidly, high KE
Exert pressure, but can be compressed into a smaller volume
PlasmaPlasma
very high KE - particles collide with enough energy to break into charged particles (+/-)
gas-like, no definiteshape or volume
stars, fluorescentlight bulbs, TV tubes
Thermal ExpansionThermal Expansion
Most matter expands when heated & contracts when cooled
Temp causes KE - Particles collide with more force & spread out
Examples: Sidewalk dividersThermometers
Changes of StateChanges of State
Changing states of matter requires energy
Changes of StateChanges of State
Evaporation =
Condensation =
Melting =
Freezing =
Sublimation =
Liquid -> Gas
Gas -> Liquid
Solid -> Liquid
Liquid -> Solid
Solid -> Gas
ConservationConservation
Law of Conservation of MassMass cannot be created or destroyedMass of reactants = mass of products
Law of Conservation of EnergyEnergy cannot be created or destroyedEnergy is converted from one form to
another
Part 2Part 2
Looking at matter and observing its qualities
Physical PropertiesPhysical Properties
Properties that do not change the chemical nature of matter
Examples: color, smell, freezing point, boiling point, melting point, magnetic attraction or repulsion, texture, volume, mass, weight, viscosity and density
Physical PropertiesPhysical Properties
List some physical properties:
Chemical PropertiesChemical Properties
Properties that do change the chemical nature of matter
Examples are: flammability, reactivity with water, pH, types of bonds
Physical ChangesPhysical Changes
A change in the physical form or properties of a substance that occurs without a change in composition
Examples: change in state, dissolving, breaking, changing shape
Can usually be reversed
Physical ChangesPhysical Changes
Name the physical change occurring:
Melting
Condensation
Boiling
Physical ChangesPhysical Changes
Evaporation
Physical ChangesPhysical Changes
Sublimation
Chemical ChangesChemical Changes
A change that occurs when a substance changes composition by forming one or more new substances
Examples: burning, rusting, cookingHints: heat or light may be given off,
smell or color change
What Type of Change?What Type of Change?