CHAPTERS ONE & TEN – MATTER AND CHANGE SOUTH LAKE HIGH SCHOOL SCIENCE DEPARTMENT MS. SANDERS Chemistry

Classifying Matter Matter Anything with mass and volume Pure Substance Matter with constant composition Mixture Matter with variable composition Element Substance made up of only one type of atom Compound Two or more elements that are chemically combined Heterogeneous Mixture Mixtures that are made up of more than one phase; not uniform throughout Homogeneous Mixture (Solutions) Mixtures that are made up of only one phase; uniform throughout Gold, Silver, Carbon, Oxygen, Hydrogen Water, Carbon Dioxide, Sodium Bicarbonate, Carbon Monoxide Sand, Soil, Italian Salad Dressing Chicken Soup, Pizza, Chocolate Chip Cookies Salt Water, Pure Air, Metal Alloys, Seltzer Water

Classifying Matter Diagram

Classifying Matter Picture Chart

Properties of Matter Property – may be a characteristic that defines an entire set of substances  Extensive - depend on amount of matter present  Volume, mass, length, and amount of energy in substance  Intensive – do NOT depend on amount of matter present  Melting /boiling point, density, and ability to conduct electricity and transfer heat, color, and malleability  They are the same for a given substance regardless of how much matter is present Properties can be PHYSICAL or CHEMICAL

Properties of Matter Physical property – characteristic that can be observed or measured without changing the identity of the substance  Color, size, luster, smell  Melting/ boiling point – solid water to liquid water Physical change – a change that does not involve a change in the identity of the substance  Grinding, cutting, melting, boiling  If you melt a block of ice, you still have water!

Properties of Matter Chemical property – a substance’s ability to undergo changes that transform it into different substances  New substance is formed  Add water to something (sodium metal changes to sodium hydroxide)  Color change, formation of precipitate, heat given off, formation of a gas Chemical change (chemical reaction) – change in which one or more substances are converted into different substances Reactants – substances that react Products – substances that are formed or produced

Elements Regions of the Periodic Table

Elements The vertical columns of the periodic table are called groups, or families. Each group contains elements with similar chemical properties. The horizontal rows of elements in the periodic table are called periods. Physical and chemical properties change somewhat regularly across a period.

Elements Types of Elements  Metals A metal is an element that is a good electrical conductor and a good heat conductor. Properties of metals most are solids at room temperature malleable - they can be hammered or rolled into thin sheets ductile - they can be drawn into a fine wire conduct electricity and heat well

Elements Metals: gold, copper, and aluminum

Elements Types of Elements  Nonmetals A nonmetal is an element that is a poor conductor of heat and electricity. Properties of nonmetals many are gases solids are brittle poor conductors of heat and electricity

Elements Nonmetals: carbon, sulfur, phosphorus, and iodine

Elements Types of Elements  Metalloids A metalloid is an element that has some characteristics of metals and some characteristics of nonmetals. Properties of metalloids all metalloids are solids at room temperature semiconductors of electricity

Elements Types of Elements  Noble Gases elements in Group 18 of the periodic table generally unreactive gases at room temperature

States of Matter Solid – definite volume and shape  Particles form crystal lattice, barely moving – slight vibration Liquid – definite volume but indefinite shape  Particles farther apart, moving around more Gas – neither definite volume nor shape  Particles are furthest apart, moving most Plasma – high temperature physical state of matter in which atoms lose most of their electrons  fluorescent bulbs

States of Matter Water in Three States

Kinetic-Molecular Theory Based on the idea that particles of matter are always in motion Can be used to explain the properties of solids, liquids, and gases in terms of energy and forces that act between them Ideal Gas vs. Real Gas:  Ideal Gas – hypothetical gas that fits all assumptions of the kinetic-molecular theory (gases with particles that have little attraction such as noble gases)  Real Gas – gas that does not behave completely according to the assumptions of the KMT (at very high pressures and low temperatures and the kinetic energy is insufficient)

Kinetic-Molecular Theory Five Assumptions:  1) Gases consist of large numbers of tiny particles that are far apart.  2) Collisions between gas particles and with their container walls are elastic collisions (no net loss of total kinetic energy).  3) Gas particles are in continuous, rapid, random motion.  4) There are no forces of attraction between gas particles.  5) The temperature of a gas depends on the average kinetic energy of the particles of the gas.

States of Matter Properties of Gases  No attraction between particles – fills all available space in container  Particles are in rapid, constant motion and they collide and glide past each other – fluid  Particles travel in a straight line  Low density  Compressible – a lot of space in between particles

States of Matter Properties of Liquids  Particles are attracted to each other  Intermolecular attractions keep the particles close together – has a definite volume and takes the shape of its container  Have kinetic energy (constant motion) and particles flow past each other – fluid  Intermolecular attractions reduce the amount of space in between particles – more dense than gases

States of Matter Properties of Solids  Particles do not freely move – vibrate in place – definite shape and volume  Orderly arrangement of particles  Particles in a fixed location – do not flow  Packed tightly together – are dense and not easy to compress

Changes of State Possible Changes of State

Changes of State Mercury in Three States (Phases)

Changes in State Phase Diagram for Water

Changes in State Phase Diagram for Carbon Dioxide

Changes in State

Water Molecule Structure of Water: Water molecules consist of two atoms of hydrogen and one atom of oxygen united by polar-covalent bonds. The molecules in solid or liquid water are linked by hydrogen bonding.  The number of linked molecules decreases with increasing temperature. Ice consists of water molecules in the hexagonal arrangement.

Water Molecule Ice and Water

Water Heating Curve for Water

Water Physical Properties of Water: At room temperature, pure liquid water is transparent, odorless, tasteless, and almost colorless. The molar enthalpy of fusion of ice is relatively large compared with the molar enthalpy of fusion of other solids. Water expands in volume as it freezes, because its molecules form an open rigid structure.  This lower density explains why ice floats in liquid water.

Water Continue Physical Properties of Water: Both the boiling point and the molar enthalpy of vaporization of water are high compared with those of nonpolar substances of comparable molecular mass.  The values are high because of the strong hydrogen bonding that must be overcome for boiling to occur. Steam (vaporized water) stores a great deal of energy as heat.

Water