Elements, Compounds, Mixtures Chapter 5 Elements, Compounds, Mixtures
Section 1: Elements
Vocabulary Element Pure substance Metal Nonmetal Metalloid
Vocabulary Element Pure substance Substance that cannot be broken down or be separated into simpler substances by chemical means Pure substance Either an element or a single compound, that has definite chemical and physical properties
Vocabulary Metal Non Metal Metalloid Element that is shiny, good conductor of heat & electricity Non Metal Does not conduct heat or electricity Metalloid Element with properties of both metal and nonmetal
Elements, the simplest substance Elements are pure Made of atoms Each element, only has one type of atom Silver only has silver atoms in it Each atom in an element is identical to each other
Classifying Elements Each element is classified by its unique properties These properties don’t change based upon the amount of the element 10 kilograms of silver has the same properties of 1 milligram of silver
Classifying Elements Characteristic properties include both physical and chemical properties Hardness, melting point, density Reactivity or flammability These properties can be used to identify elements
Grouping Elements 3 major groups of elements Metal Nonmetal Metalloid
Grouping Elements Metals Good conductors of heat Good conductors of electricity Malleable Can be shaped Ductile Can be drawn into wires
Grouping Elements Nonmetals Dull Poor conductors of heat & electricity Not shiny Poor conductors of heat & electricity Solids tend to be brittle Unmalleable Few objects made of purely of nonmetals
Grouping Elements Metalloids Semi-metals Have properties of both metals & nonmetals some are shiny Some conduct electricity Some are dull Some malleable Etc….
Section 2: Compounds
Vocabulary Compound Pure substance composed of 2 or more elements that are chemically combined
Compound: Made of Elements Elements combine through chemical changes Chemical changes mean a new substance Think water Hydrogen gas + oxygen gas = water
Compound: Made of Elements Chemical changes (reactions) rearrange the atoms Form in various patterns Properties of new substance are different than original atom.
Properties of Compounds Compounds have unique properties from the elements that made it Always join in specific ratios
Breaking Down Compounds Compounds can only be broken by chemical changes Example --- soda Carbonic acid is release from the water/sugar Creates that fizz Fizz or bubbles is a sign of chemical change
Breaking Down Compounds Chemical breakdown is harder than physical changes Generally energy is needed for a chemical change
Compounds in Your World Compounds are everywhere in your world Industry Plastics Metal alloys Nature Water Sucrose (sugar)
Section 3: Mixtures
Vocabulary Mixture Solution Solute Solvent Concentration Solubility
Vocabulary Mixture Solution Solute Combination of 2 or more substances that are not chemically combined Solution Homogenous mixture 2 or more substances are evenly dispersed Solute Item to be dissolved
Vocabulary Solvent Concentration Solubility substance that dissolves the solvent Concentration Amount of a particular substance in a given quantity of a mixture or solution Solubility Ability of a substance to dissolve
Properties of Mixtures No chemical changes So substance still has same chemical make up Can be separated by physical method
Properties of Mixtures Common Ways to Separate mixtures Distillation Magnet Centrifuge
Properties of Mixtures Ratios of particles in a mixture can vary Remember that in compounds, the ratio is fixed
Solutions Homogenous mixture Particles are evenly mixed throughout
Solutions
Solutions Examples Soda Gasoline Air Alloys Mix of 2 or more metals
Concentration of Solution Amount of solute in solvent Normally expressed in grams per milliliter Solubility of a solute depends on temperature Normally higher solubility with higher temperature