Investigating Matter

Matter Matter is the “stuff” in things. It has weight or mass and takes up space or volume.

The States of Matter On earth, matter has three common states: solid, liquid and gas.

Plasma : Matter’s Fourth State In the universe, matter has a fourth state, Plasma, which is found in stars.

Measuring Matter : Mass The mass of an object is measured with a balance or scale. The units of mass are grams (g) or kilograms (kg)

Measuring Matter : Volume The volume of a regular-shaped piece of matter can be determined by measuring its dimensions and multiplying these.

Measuring Matter : Volume The volume of a liquid can be determined by using a graduated cylinder. The bottom of the meniscus indicates the correct volume. Cubic units of volume are cubic-centimetres (cm 3 ), cubic decimetres (dm 3 ). Capacity units of volume are litres (L) or millilitres (mL)

Measuring Matter : Volume The volume of an irregular-shaped solid can be determined by a water displacement method. The units of volume are cubic-centimetres (cm 3 ), cubic decimetres (dm 3 ), etc., litres (L) or millilitres (mL)

Energy Energy is what makes things move, go or happen. Energy has NO weight and NO volume.

Forms of Energy Energy has many forms including: Light, heat, chemical, kinetic, electrical, potential, nuclear, and sound.

Kinetic and Potential Energy Kinetic energy is the energy moving things have. Potential energy is energy stored in an object.

Energy Changes From One Form To Another

Potential Energy Changing To Kinetic Energy

Chemical and Physical Changes Chemical changes produce new substances but physical changes just make a new form of the same substance.

Physical Changes : Easily Reversed A physical change usually involves a change of state. Physical changes are usually easily reversed and produce just a new form of the same substance.

Physical Changes of Water Adding heat to ice (solid water) creates liquid water and adding heat to liquid water creates steam or water vapour (water gas)

Chemical Changes Chemical changes produce new substances. Chemical changes are difficult or impossible to reverse.

Changes that Mean a Chemical Change has Happened 1.A colour change means a chemical change has happened. 2.When a gas is produced a chemical change has happened. 3.A change in odour has happened. 4.Light or heat is being given off. 5.There has been a large change in temperature (up or down) 6.A solid (ppt - precipitate) has been formed when two liquids are mixed.

The Kinetic Molecular Theory 1.All matter is made up of small particles. 2.There is empty space between the molecules.

The Kinetic Molecular Theory 3. Particles are constantly moving and colliding with each other. a. Particles of solids are tightly packed and only vibrate about fixed points. b. Particles of liquids are farther apart and move past each other. c. Particles of gases are very far apart and move quickly.

The Kinetic Molecular Theory 4. The amount of particle motion depends on the amount of heat energy they have. The more heat, the faster and farther apart the particles move.

Temperature and Changes of State As heat is added, solids melt to liquids. As heat is added, liquids change to vapours or gases. As heat is removed, gases condense to liquids. As heat is removed, liquids change into solids (freeze).

What Change of State is Shown?

Cooled bacon grease

What Change of State is Shown? Dry ice (solid carbon dioxide)

What Change of State is Shown? Hoar Frost

Physical and Chemical PROPERTIES Physical properties are properties a substance has by itself. –Example: Limestone is gray-white in colour. It hardness is 3-4 on the Mohs scale. Its density is g/cm 3.

Physical and Chemical PROPERTIES Chemical properties are properties a substance has when placed in contact with another substance. –Example: Limestone fizzing when an acid is dripped onto it.

Some Physical Properties of Substances Malleability: The ability to hammer a substance into various forms and thin sheets.

Some Physical Properties of Substances Boiling Point: The temperature at which a substance changes from a liquid to a solid throughout the liquid (not just at its surface).

Some Physical Properties of Substances Ductility: The ability to pull a substance into thinner shapes and wires.

Some Physical Properties of Substances Conductivity: The ability of a substance to conduct heat or electricity.

Some Physical Properties of Substances Solubility: The ability of a substance to dissolve in a solvent like water or some other solvent.

Some Physical Properties of Substances Crystallinity: The degree to which a substance has a crystal order inside it.

Some Physical Properties of Substances Viscosity: For liquids, it is how “thick” they are when they flow along. Water has a low viscosity while honey has a high viscosity.

Pure and Impure Substances A pure substance is made up only of particles of one kind. Pure substances have fixed properties that do not change from sample to sample. Elements and compounds are pure substances. An Impure substance is a mixture of more than one kind of particle. Impure substances have variable properties that can change from one sample to another.

Elements An element is a pure substance that can NOT be broken down or separated into simpler substances. Elements are made up atoms or molecules which have atoms of one kind.

Compounds A compound is a pure substance that is made up of two or more elements and can be broken down into these simpler elements. Water is a compound which can be broken down into hydrogen and oxygen gas by electricity.

Compounds Compounds are made up of molecules which are identical but which have two or more kinds of atom per molecule.