States of matter and Classification of Matter CHAPTERS 14.1 and 15 States of matter and Classification of Matter

Classification of Matter ESSENTIAL QUESTIONS: WHAT IS MATTER? WHAT ARE THE STATES OF MATTER? HOW DO WE CLASSIFY MATTER? WHAT ARE PHYSICAL AND CHEMICAL CHANGES?

Matter Anything that has mass and volume Found in a variety of forms Can be changed from one form to another (Law of Conservation of Mass)

States of Matter Kinetic Theory of Matter – states that all particles of matter are in constant motion The rate at which atoms in a substance move determines its state

Solid Molecules tightly linked together in a definite shape Vibrate in place Fixed volume and shape

Liquid Molecules NOT as tightly linked as a solid Maintains a fixed volume Able to flow & takes the shape of the container

Gas Molecules have little or no attraction to each other Fill the volume of the container Move very rapidly

Plasma MOST COMMON STATE OF MATTER IN THE UNIVERSE! No definite shape or volume A portion of the particles are IONIZED Acts like a gas but responds to electromagnetic fields

Phase Change A reversible physical change that occurs when a substance changes from one state of matter to another Temperature does not change during a phase change Thermal energy must be added or removed to cause a substance to change state

Phase Change Graph

Changing States of Matter

Changing States of Matter Endothermic Reactions – absorb energy Melting – ie. ice cubes Vaporization – liquid  gas ie. boiling / evaporation / standing water Sublimation – solid  gas without liquid phase ie. dry ice

Changing States of Matter Exothermic Reactions – release energy Freezing – ie. ice cubes Condensation – gas  liquid ie. morning dew Deposition – gas  solid without liquid phase ie. frost on windows

Changing States of Matter

Composition of Matter Properties of materials are used to classify them. The two main categories are PURE SUBSTANCES and MIXTURES

PURE SUBSTANCES A type of matter with a fixed composition. ELEMENT: a substance that contains ONE TYPE of atom: copper, carbon (graphite/diamond) and oxygen (O2)..

PURE SUBSTANCES A type of matter with a fixed composition. COMPOUND: a substance in which the atoms of two or more elements are combined in a fixed proportion: H2O, CaCO3, CO2, and NaCl. The compound properties are often different from the elements that make them

MIXTURES A type of matter with NO fixed composition. HETEROGENEOUS MIXTURES: different materials are distinguished easily: pizza, soup mix, and granite. Not all are easily recognized

MIXTURES HOMOGENEOUS MIXTURES: contains two or more gaseous, liquid or solid substances blended evenly throughout: soda, air, sea water, and vinegar. These are also known as SOLUTIONS: a homogeneous mixture of particles that are CONSTANTLY and UNIFORMLY mixed.

MIXTURES COLLOID: a mixture with particles that are larger than a solution, but not heavy enough to settle out: milk (water, sugars, fats, proteins), paint (oil, pigment, etc), fog (air, liquids), and smoke in air.

MIXTURES SUSPENSIONS: heterogeneous mixture containing a liquid in which the particles settle.

Physical Properties of Matter Physical Properties: Any characteristic of a material that can be observed or measured without changing the composition of the substances in the material. E.g. viscosity, conductivity, malleability, hardness, melting point, boiling point, and density are examples of physical properties.

PROPERTIES OF MATTER Using physical properties to separate – sifting, sorting, using a magnet, etc. RECYCLING. Need to add in slide about Physical

Section 15.2: PHYSICAL & CHEMICAL CHANGES OF MATTER PHYSICAL CHANGE: a change in size, shape, or state of matter. THE IDENTITY REMAINS THE SAME. These changes may involve energy changes but the properties don’t change. E.g. iron when heated.

PHYSICAL & CHEMICAL CHANGES OF MATTER PHYSICAL CHANGE: a change in size, shape, or state of matter. THE IDENTITY REMAINS THE SAME. DISTILLATION – Uses a physical change to separate (evaporation). Used in industry.

Using Properties to Separate Mixtures Filtration is another separation method. Filtration is a process that separates materials based on the size of their particles. Some examples: Panning for Gold, archaeologist.

CHEMICAL PROPERTIES & CHANGES CHEMICAL PROPERTY – A characteristic of a substance that indicates whether it can undergo a certain chemical change. E.g. flammable, changes color.

CHEMICAL PROPERTIES & CHANGES CHEMICAL CHANGE – produces heat, light, sound, color change, precipitate, and gas bubbles.

PHYSICAL & CHEMICAL CHANGES FOR EXAMPLE: WEATHERING Physical – rocks broken apart by ice, streams carving away rock, wind moving sand Chemical – Limestone (CaCO3) changes to gypsum in acid