Matter and Change Chapter 1

Chemistry is a Physical Science Chemistry – The study of the composition, structure, and properties of matter, and the changes it undergoes

Branches of Chemistry 1. Organic Chemistry – the study of compounds that contain carbon 2. Inorganic Chemistry – the study of compounds that do not contain carbon 3. Physical Chemistry – the study of the properties and changes of matter and the energy involved in a reaction 4. Analytical Chemistry – the identification of the components of a sample 5. Biochemistry – the study of reactions that occur in living things 6. Theoretical Chemistry – the use of mathematics and computers to design and predict the properties of new compounds

Research 1. Basic research is carried out for the purpose of increasing knowledge 2. Applied research is carried out to solve a problem 3. Technological development involves the production and use of a product

Matter and Its Properties Atom – the smallest part of an element that has the properties of that element Element – a pure substance made of only one kind of atom Compound – a substance formed when atoms of different elements are bonded together

Some Criteria for the Classification of Matter Properties State (solid, liquid, gas) Composition

Properties Intensive -Do not depend on amount of matter. Extensive -Depend on amount of matter.

Intensive and Extensive Properties Sulfur

Properties Physical: observed without changing the composition of the substance. Chemical: the ability of a substance to undergo a specific chemical change

Examples of Physical Properties Include melting point, boiling point, density, color, odor, state of matter, hardness

Physical Changes Do not change the identity of the substance Include changes of state (freezing, melting, vaporization, condensation)

SubstanceStateColor Melting Point (C°) Boiling Point (C°) Density (g/cm 3 ) OxygenO2O2 GasColorless MercuryHgLiquidSilvery- white BromineBr 2 LiquidRed-brown WaterH2OH2OLiquidColorless Sodium Chloride NaClSolidWhite Example: Physical Properties

States of Matter Solid has definite shape and definite volume Liquid Has definite volume but takes the shape of the container Gas takes the volume and shape of its container Plasma Exist at very high temperatures & involves atoms which have lost their electrons

Solid Liquid Gas

Bromine Gas (Vapor) Liquid

Change of Phase Meltingsolid  liquid Condensationgas  liquid Freezingliquid  solid Evaporationliquid  gas Sublimationsolid  gas Boiling: Evaporation occurring beneath the liquid’s surface.

Chemical Properties 1. Describe how the substance reacts with another substance 2. Burning and rusting are examples

Chemical Changes (Chemical Reactions) 1. New substances formed 2. Reactants – the substances which react 3. Products – the new substances with are formed 4. Sodium + chlorine yields sodium chloride (reactants)(product)

Burning of Magnesium 2Mg+ O 2  2MgO

Mixture A physical blend of two or more substances which each keep their own identity

Mixture Composition varies with different samples A homogeneous mixture (solution) is uniform in composition throughout a sample A heterogeneous mixture has different composition in different places Mixtures can be separated Filtering Distillation Centrifuge Paper chromatography

Pure Substances Includes elements and compounds Every sample has exactly the same composition

Classification of Matter (by composition)

Example: Stainless Steel A homogeneous mixture of: -Iron (Fe) -Chromium (Cr) -Nickel (Ni)

Copper II Sulfate and its solution in water.

Example: Gaseous Mixture Elements argon and nitrogen and a compound (water vapor).

Heterogeneous Mixtures Non-uniform composition throughout the mixture Two or more phases. Example: Oil and vinegar

Note: Mixtures can be physically separated. Mixtures exhibit physical properties similar to the components of the mixture.

Example: Separate iron filings from sulfur using a magnet.

Filtration: separates a solid from a liquid in a heterogeneous mixture

Distillation: - separate dissolved solids from a liquid -uses boiling and condensation.

Distillation of Crude Oil (Refining) Crude Oil is a mixture of Hydrocarbons

Distillation of Crude Oil

Elements –(not in your notes) The simplest substances. Can not be separated into simpler substances. Building blocks of all matter. More than 100 known elements. Represented by chemical symbols.

Chemical Symbols of Elements (not in your notes) System started by Jons Berzelius (Sweden, ) One or two first letters of name of the element. Many elements names have roots from: Latin, Greek, mythology, geography, names of scientists.

Examples: Americium, Am Einsteinium, Es Bromine, Br Helium, He Lead(Plumbum), Pb Niobium, Nb Iron (Ferrum), Fe Mendelevium, Md

Introduction to the Periodic Table Groups or Families Vertical columns on the periodic table Elements in a group have similar chemical properties Periods Horizontal row on the periodic table Each element in a period has different properties The two rows at the bottom are called the Lanthanide Series and the Actinide Series

Metals Located on the left side of the periodic table Good conductors of heat and electricity Can be hammered into thin sheets (malleable) and drawn into a wire (ductile) Nonmetals Located on the right side of the periodic table Those that are solid tend to be brittle and poor conductors Metalloids Located along the stair-step line Have properties of both metals and nonmetals Semiconductors Aluminum is a metal

Transition Metals are located in short columns Noble Gases Elements in Group 18 Generally do not form compounds