Unit 1 - Introduction to Chemistry What Matters? 1.A.2(b) – use appropriate SI units…describe the relationship among SI unit prefixes
SI Base Units 1.A.2(b) – use appropriate SI units…describe the relationship among SI unit prefixes Length – meter Mass – kilogram Time – second Temperature – Kelvin Quantity of Matter – mole Volume - liter This will be on the test
SI Derived Units Combinations of base units Ex – velocity = meters/second (m/s) acceleration = meters/second ∙ second m/s2) density = kg/m∙m∙m (kg/m3)
Non-SI Units Length – foot, mile, Mass – ounce Temperature – Centigrade, Celsius, Fahrenheit Volume - gallon
Commonly Used Prefixes Centi- 1/100 or 0.01 Kilo- 1000 or 1.0 x 103 Milli- 1/1000 or 0.001
States of Matter II.B.1(a) – compare the definition of matter and energy and the laws of conservation of matter and energy
Matter Def- anything that has mass and occupies space 3 States of matter Solid Liquid Gas
Solids, Liquids, and Gases Solids – have both definite volume and shape Liquids – have definite volume but not shape Gases – have neither definite volume or shape Particles have increasing velocity from solids to liquids to gases
II.B.2(c) – describe the phase and energy changes associated with them Changes of State II.B.2(c) – describe the phase and energy changes associated with them
Phase Changes Melting Freezing Vaporization/Evaporation Condensing Sublimation Deposition
Melting/Freezing Energy must be ADDED for a substance to melt Energy must be REMOVED for a substance to freeze
Vaporization & Condensation Energy must be ADDED for a substance to boil Energy must be REMOVED for a substance to condense
Deposition/Sublimation Energy must be ADDED for a substance to sublime Energy must be REMOVED for a substance to undergo deposition
Law of Conservation of Energy Energy cannot be created or destroyed Energy of a reaction MUST be conserved
Law of Conservation of Matter Matter cannot be created or destroyed Mass of a chemical reaction MUST be conserved
Elements, Compounds & Mixtures II.A.2(b) – compare the characteristics of elements, compounds and mixtures
Elements An element is matter in its simplest form Cannot be broken down by chemical means Periodic Table (118 elements)
Compounds Are combinations of elements Have the same composition Can be broken down by chemical means
Mixtures Have variable composition Can be separated physically or chemically Homogeneous Mixtures – are the same throughout Heterogeneous Mixtures – have different regions
Separatory Techniques IV.A.1(b) – describe and perform common separation techniques
Filtration Used for separating undissolved solids Pour through a mesh (filter paper)
Distillation Used to separate dissolved solids or liquid mixtures Uses physical changes
Chromatography Uses chemicals to separate the pigments of plant or chemicals Various Methods Gas chromatography Liquid chromatography Thin-layer chromatography Ion-exchange chromatography
Chemical vs Physical II.B.1(e) – define chemical and physical properties and compare them by providing examples
Physical Properties Physical Properties… Odor Color Volume State Can be observed without changing a substance into another substance. Boiling point, density, mass, volume, etc. Odor Color Volume State Density Boiling point Melting point
Chemical Properties Chemical Properties… Wood burning Iron rusting Can only be observed when a substance is changed into another substance. Flammability, corrosiveness, reactivity with acid, etc. Wood burning Iron rusting Digestion photosynthesis
Chemical and Physical Changes II.B.1(d) – explain the difference between chemical and physical changes and demonstrate how these changes can be used to separate mixtures and compounds into their components
Physical Change These are changes in matter that do not change the composition of a substance. Changes of state, temperature, volume, etc.
Chemical Change Chemical changes result in new substances. Combustion, oxidation, decomposition, etc.
Indicators of Chemical Change Formation of a gas (bubbles) Formation of a precipitate (solid) Change in temperature Exothermic Endothermic Color change
Properties Extensive Properties – depend on the amount of substance present Volume Mass Energy present Intensive Properties – do NOT depend on the amount of substance present Melting point Boiling point Density Conductivity
Elements & The Periodic Table Periods – horizontal rows Groups – vertical columns Group 1A – alkalai metals Group 2A – alkalai earth metals Group 3A-12A – transition metals Group 16A – chalcogens Group 17A – halogens Group 18A – noble gases
Group 1 – Alkali Metals
Group 2 – Alakali Earth Metals
Transition Metals
Chalcogens
Halogens
Noble Gases
The Periodic Table
Metals Conduct heat and electricity Malleable Ductile Luster (shiny)
Non-metals Poor conductors of heat Poor conductors of electricity Many are gases at room temp 5 solid non-metals Phosphorous Sulfur Carbon Selenium Iodine
Metalloids Have some characteristics of both metals and non-metals
Noble Gases Least reactive of all elements All gases at room temp