Chem 101 1nd EditionExam #4 Study Guide This exam will cover every section from chapters 1, 2, 3, 4, 5, 6, and 8. This study guide aims to give you the tools you need to ace the upcoming exam. The exam could have anywhere from 30 to 50 questions on it and you will have two and a half hours to complete it. It is highly suggestedthat you test your abilities by retaking old exams and practice worksheets. This exam will cover matter and its forms, elements 1-38 and 49-56, the scientific method, classification of pure substances and mixtures, elements v.s. compounds, writing out chemical formulas, chemical change v.s. physical change and their properties, metric units and conversions, significant figures, density calculations, Daltons atomic theory, subatomic particles, isoptopes, orbitals, electron configurations (including abbreviated), determining atomic mass, regions of the periodic table, ionic vs. covalent, diatomic and polyatomic elements, balancing and writing out chemical equations, mole calculations, stoichiometry calculations, lewis dot structures of covalent and ionic compounds, VSEPR theory and determining the electron geometry and molecular geometry, polarity, electronegativity, Nonpolar vs. polar, whether something is an electrolyte or nonelectrolyte, total and net ionic reactions, disassociation reactions, neutralization reactions, strong and weak acids, strong and weak bases, pH scale and pH/ pOHcalculations, organic molecules, being able to identify and name organic compounds and theirfunctional groups. The subjects in bold are the ones you ought to focus on. Good luck!Lecture 1This lecture was an introduction to chapter one which focuses on matterMatter: Anything that has mass and occupies space. Particles: Is a term used to refer to atoms, molecules or ions. There are 3 primary states of matter:i. Solid: Particles of solids are uniform and closely packed to one another. Their position does not change. Particles of solids move or vibrate to a degree unless the object in question is frozen. Volume and shape are constant. When solids are heated the particles gain energy and the solid becomes a liquid.ii. Liquid: Particles of liquids are farther apart than those seen in solids but still relatively close to one another. There is no fixed arrangement of particles and they can occupy any location in the object as there is more allowance for movement. Liquids conform to the containers that hold them. When you heat a liquid it becomes a gas because you energize and excite the particles. Freeze it and it will deplete particle energy to form a solid. iii. Gas: Characterized by large gaps between particles that are moving freely at high speeds. Gas can be compressed- unlike solids or liquids because ofthe space between particles in this state. Particles are in constant motion however they never average a speed. Particles move quickly because theycontain energy. Like liquids, gas conforms to the container it is in. Matter is composed of Atoms: the smallest unit of an element that retains all of the properties of that element.Pure Substances: is any form of matter that has a uniform composition and cannot be separatedby physical methods (i.e. filtration or evaporation). Elements and Compounds are 2 subclasses of pure substancesElement: the simplest form of a molecular compound. Compounds: a substance made up of atoms from 2 or more elements. There are 2 broad categories of compounds: Molecular and Ionic. Molecules are the simplest units of a molecular compound. Formula unit is the simplest unit of an ionic compound. The type of compound a substance is depends on the type of bond present.Important to keep in mind** the elements that make up either type of compound cannot be separated by physical methods, but only by a chemical reaction.Lecture 2This lecture focuses on an introduction to mixtures, the periodic table of elements and its regions as well as an introduction to the scientific method and metric system. You need to memorize the metric units and their prefixes to do conversion calculations.Mixture: is 2 or more pure substances that are physically combined but not chemically bonded together. Mixtures have 2 subclasses:Homogeneous Mixtures: are mixtures in which the substances that compose it are so evenly distributed that a sample from any part of the mixture will be chemically identical to a sample from any other part. Alloys: are homogeneous mixtures of several metallic elements. Gasses can also form homogeneous mixtures.Heterogeneous Mixtures: is one in which the composition varies from one region of the sampleto another. The Periodic Table of Elements: This shows all the known chemical elements. Several patterns can be deciphered within the periodic table. It allows us to predict: Chemical reactions, Formulas of many compounds, Relative sizes of atoms and molecules, Whether compounds will dissolve in water or oil.i. Dmitri Mendeleev was the Russian Scientist that developed and organizedthe periodic table that we use today. He was even able to predict the existence of elements that had not been discovered yet!When interpreting the periodic table it is important to be able to decipher what the symbols and numbers represent:Atomic Symbols: Letters of ‘symbols’ are used to represent the elements of the periodic table. Most are derived from the elements name (He- Helium). However, some elements such as gold (Au) and sodium (Na) are represented by symbols derived from the Latin names of the element. Atomic Number: is the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table. This number is normally found in the top right hand corner of each elemental square. Atomic Mass: the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes. For example Sodium (Na) has an atomic number of 11, and an atomic mass of 22.990NOTE** you will need to memorize elements (symbol, proper spelling of elemental name and atomic number) 1-38 and elements 49-56Regions of the Periodic Table: It is important to be able to distinguish between elements that are metals, nonmetals or metalloids. Metals: Share the following properties: They are good conductors of electricity and heat. They are solid at room temperature.