Chemistry Final Exam Prep Guide

Chemistry Final Exam Study Guide Precipitate Insoluble solid. -Formed when two liquids are combined. Endothermic Temperature decreases. Exothermic Temperature increases. Subscript Little number after chemical symbol. Superscript Exponent number, top right corner. Coefficient Number in front of chemical symbols. Metalloids Orange on periodic table. -Boron, Silicon, Arsenic, Tellurium, Antimony, Polonium On top of staircase=non-metals Under staircase=metals Transition Metals Grey on periodic table. -Needs roman numerals in word form. Halogens Green on periodic table -Fluorine, Chlorine, Bromine, Iodine, Astatine -All have negative charges. Noble Gases All have octet, need no electrons. Pink on periodic table -Helium, Neon, Argon, Krypton, Xenon, Radon Matter Is made up of atoms. -Anything that occupies space and has mass is matter. Volume Formula: Length x width x height Mass Weight of an object. Physical change Occurs when there is a change in state, but not in chemical composition. -Original material is retained -change is reversible by means of physical separation. Ex. Melting, freezing, condensation, dissolving, boiling, mixing, cutting, tearing, chopping. -Heat may be given off Chemical Change Occurs when there is a change in chemical composition. -Formation of new material. -Irreversible by physical separation. -Color change, evolution of gas, formation of precipitate. Ex. Burning, cooking, rusting, growing, digesting Signs of a chemical reaction -Color change, formation of gas, formation of precipitate, temperature change Proton Positive charge. Electron Negative charge. Valence Electrons Number of electrons in outermost layer. Isotope When the protons stay the same and the neutrons change for the same element. Ion Charged atom that has either gained or lost electrons. Gained=negative Lost=positive Polyatomic Ion Ions. Alkali Metals Lithium, Sodium, Potassium, Rubidium, Cesium, Francium -Metals on the left most side of the periodic table (yellow) Alkaline Earth Metals Right next to Alkali Metals (Red). -Beryllium, Magnesium, Calcium, Strontium, Barium, Radium Homogeneous Mixture 1/2 Substances are composed of a single phase and are uniform in composition and properties throughout a given sample. Can only see one part. Heterogeneous Mixture Substances are composed of more than one phase-component separate into different regions. Can see two or more parts. Covalent (molecular) bond Made up of atoms that are different. Usually made up of all non-metal atoms. Ionic bond Made up of ions that are different. Compounds form crystal lattice structure. Made up of one metal and one non-metal atom. Mass number Protons+Neutrons=Mass number (Also the number under each symbol on the periodic table) Atomic Number Number of protons in an element. Atom Matter is built up from very tiny units called atoms. Neutron Neutral charge. Independent Variable The variable in an experiment that you change. Dependent Variable The variable that you are testing. Controlled Variable What stays the same. SI units Metric conversion chart. Great Mighty King Henry Died By Drinking Chocolate Malted Milk Giga, Mega, Kilo, Hecto, Deca, Base, Deci, Centi, Milli, Micro Density The measurement of the mass of an object per unit volume of that object. Formula: D=m/v Element A pure substance that cannot be decomposed into anything simpler by chemical means. Compound A pure substance made of two or more atoms that are chemically combined. There are two types of compounds: Ionic and Molecular. Mixture Composed of two or more substances (elements or compounds.) Each substance retains its own characteristic properties. -Not chemically combined substances -Can be separated by physical means. Group Number Across the top of the periodic table. Number of Valence electrons. Period Number Goes down the side of the periodic table. Number of energy levels. Synthesis A+B=AB Decomposition AB=A +B Single Displacement AB+C=CB+A Double Displacement AB+CD=AD +CB Combustion Carbon Compound+O=H2O + CO2 States of Matter Solid, liquid, gas 2/2