Properties and Changes of Matter Unit One Chapter 2

Properties of Matter What is Matter? –Anything that has mass and takes up space What is mass? –Amount of matter an object contains

Types of Matter Substance –Matter that has definite and uniform composition Mixture –Physical blend of two or more substances that can be separated using physical means. Filtration Distillation

Types of Matter More than one type of “stuff” together One type of “stuff”

Types of Substances Elements –Simplest form of matter Compounds –composed of more than one type of atom –Can be separated into simpler substances by chemical means

Types of Mixtures Heterogeneous –Multiple phases Homogeneous –All in a single phase

Homogeneous Mixtures are Solutions Solvent –The substances that does the dissolving –Present in the greater amount Solute –The substances that gets dissolved –Present in the smaller amount

Heterogenous or Homogeneous Saltwater Spaghetti sauce Muddy water Cough syrup Salad Brass

Physical Properties of Matter –Quality of a subtance that can be observed or measured without changing the substance Melting/boiling point, color, density. Mass

Types of Physical Properties Two types of Physical Properties –Intensive Are constant regardless of the amount of the substance –Melt. Pt/Boil. Pt –Density –Extensive Vary depending on amount of substance present –Mass –Volume Intensive properties are inherent to a substance and can aid in identifying an unknown sample

Phases of Matter 3 common phases –Solid Definite shape Definite volume Highly rigid and organized – particles vibrate around fixed points Nearly incompressible, does not flow –Liquid Definite volume Indefinite shape Fluid – takes the shape of its container, slightly compressible –Gas Indefinte shape – Indefinite volume Very fluid - takes shape and volume of containter Particles move randomly with high energy, very compressible soli d

Additional Phases of Matter Bose-Einsten Condensate –Exists as temperatures approach absolute zero (-273 °C) –Extremely dense, but less structured than solid Plasma –Energy similar to gas –Contains ions rather than atoms Attraction of ionic charges pull molecules closer together than in gas

Definitions related to changes in Matter Vapor –Gaseous state of a substance that is in the liquid or solid state at normal temperatture Temperature –Average kinetic energy of the particles (atoms, molecules, etc.) of the substance

Physical Changes to Matter Changes that do not alter the chemical compostion Change in size or shape Change in phase

Chemical Properties of Matter Ability of a substance to react and form a new substance –Can only be observed or measured by changing the substance into a different substance

Chemical Changes to Matter Results in the formation of a new substances –A chemical reaction takes place Evidence that a chemical reaction has taken place –Change in energy Temperature increase or decrease –Production of a gas Formation of bubbles or detection of odor –Formation of a precipitate Presence of a solid –Color change

Chemical Reactions One or more substances change into a new substance –Reactants The substances that exist before the reaction/chemical change takes place –Products The substances that form as a result of the reaction/chemical change

Evidence of a Chemical Reaction Formation of a gas Formation of a solid (precipitate) Color change Change in energy (absorbed or given off)

Practice: classify the following as physical or chemical properties of water 1.Colorless 2.Changes from a liquid to a gas at 100ºC 3.Decomposed by electricity into hydrogen and oxygen 4.Freezes at 0 ºC 5.Produces acetylene gas when dropped in calcium carbide 6.Produces a gas when reacted with sodium

Practice: Classify the following as physical or chemical changes: 1.Bending a piece of wire into a new shape 2.Cooking a steak 3.Cutting the grass 4.Souring of milk 5.Burning coal 6.Dissolving sugar in water 7.Growing grass 8.Stretching a rubber band

Law of Conservation of Mass The amount of matter present before the reaction takes place will equal the amount of matter at the completion of the reaction

Food for Thought: If 4.0 g of hydrogen are combined with a mass of oxygen to make 36.0 g of water, how many grams of oxygen were used in the reaction?