•Matter is anything that has mass and takes upspace.
•Matter can have both physical and chemicalproperties.
What is matter?
•Any characteristic of matter that you can observewithout changing the identity of the substancesthat make it up is a physical property.
•State of matter, temperature, and the size of anobject are all examples of physical properties.
What are physical properties?
•Physical properties can be size dependent or sizeindependent.
•A size dependent property changes with the sizeof the sample: mass, volume, size, weight.
•A size independent property stays the same nomatter what size the sample is: density, color,boiling or melting point, etc…
What are physical properties?
•Weight is the gravitational pull on the mass of anobject.
•Weight depends on the location of an object, butits mass does not.
What are physical properties? (cont.)
Volume depends onthe amount or size ofthe sample of matter.
Hutchings Photography/Digital Light Source
•Density is constant for a given substance,regardless of the size ofthe sample.
What are physical properties? (cont.)
•Magnetism, malleability, and electrical conductivity arealso physical properties.
•Color, texture, shape are also physical properties (whatare some more?)
•Melting point, freezing point, condensation point andboiling point are physical properties.
What are physical properties? (cont.)
•The melting point is the temperature at which asolid changes to a liquid.
•The freezing point is the temperature at which aliquid changes to a solid.
•The boiling point is the temperature at which aliquid boils, or changes to gas.
•The condensation point is the temperature atwhich a gas condenses or changes to liquid.
What are physical properties? (cont.)
•A chemical property is the ability or inability of asubstance to combine with or change into one ormore new substances.
•A chemical property is a characteristic of matterthat you observe as it reacts with or changes intoa different substance.
What are chemical properties?
•Flammability and the ability to rust are bothchemical properties.
•Flammability is the ability of a type of matter toburn easily.
•Rust is a substance that forms when iron reactswith water and oxygen.
What are chemical properties? (cont.)
•Physical properties are useful for identifyingunknown substances.
•When you identify matter using physicalproperties, consider how the properties are alikeand how they are different.
Identifying Matter Using PhysicalProperties
Physical properties and chemical properties areuseful for sorting materials.
Physical properties, such as a material’s meltingpoint, are useful for separating different types ofmatter that are mixed.
Sorting Materials Using Properties
•All matter is made of tiny particles that areconstantly moving.
•In solids, particlesvibrate back andforth in alldirections.
States of Matter (cont.)
In liquids, the distance between particles is greaterand they can slide past one another.
States of Matter (cont.)
States of Matter (cont.)
In a gas, particles move freely rather than stayingclose together.
•Particles of matter that are close together exertan attractive force on each other.
•The strength of the attraction depends on thedistance between particles.
States of Matter (cont.)
•Matter can change in many physical and chemicalways.
•A change in the size, shape, form, or state ofmatter that does not change the matter’s identityis a physical change.
•When a physical change occurs, the chemicalproperties of the matter stay the same.
What are physical changes?
Dissolving: A Physical Change
Hutchings Photography/Digital Light Source
•Changes in the state of matter are physicalchanges.
•Melting and boiling are both changes in state.
•Changes in energy cause changes in the state ofmatter.
What are physical changes? (cont.)
Hutchings Photography/Digital Light Source
•A chemical change is a change in matter in whichthe substances that make up the matter changeinto other substances with different chemical andphysical properties.
•The new substance produced during a chemicalchange has different chemical and physicalproperties.
What are chemical changes?
What are chemical changes? (cont.)
The only sure sign of a chemical change is theformation of a new substance.
•For many reactions, changes in physical properties,such as color or state of matter, are signs that achemical change has occurred.
•All chemical reactions involve energy changes.
•Thermal or light energy is often needed for achemical reaction to take place.
What are chemical changes? (cont.)
•Most chemical changes cannot be reversed.
•Some physical changes can be easily reversed, butothers cannot.
What are chemical changes? (cont.)
The law of conservation of mass states that thetotal mass before a chemical reaction is the sameas the total mass after the chemical reaction.
What are chemical changes? (cont.)
•Sometimes deciding if a change is physical orchemical is easy, but often many factors must becompared and considered.
•Chemical changes produce a new substance, butphysical changes do not.
Comparing Physical andChemical Changes
