CH 115 1st Edition Lecture 2Unit 1: Atoms, Isotopes and IonsOutline of Current Lecture I. IntroductionA. What is Chemistry and Why it MattersII. Types of Matter and Chemical SymbolismA. Definition of Matteri. Definition of elements, compounds, atoms and moleculesii. Atomic TheoryB. Chemical SymbolismIII. The Periodic TableA. Basic InformationB. Different Categories of ElementsC. Breakdown of Important Groups and PeriodsCurrent LectureIntroductionChemistryis the study of matter and its transformations. In class, we learned that chemistry actually stemmed from Alchemy, a medieval science that was well believed to transmute lead (atomic number 82) into gold (atomic number 79). In order to achieve this feat, scientists would have to decrease the atomic number (or number of protons) of lead from 82 to 79. This proved to be exceedingly difficult for early scientists simply because it is impossible to use chemical means to remove 3 protons from lead. Today, however, particle accelerators can be used to forcibly subtract protons. This method makes the goals that early alchemists had These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.possible, but changing the number of protons through particle acceleration is ironically more costly than the gold itself! Understanding chemistry is crucial because it is all around us! Everything we involve ourselves with on a day-to-day basis, from eating to going outsideto playing on a smartphone, allinclude countless chemical reactions. Mastering this science will equip you with the tools neededto comprehend and improve the world we all share.Types of Matter and Chemical SymbolismTo truly learn and understand chemistry, it is important to know about matter and chemicalsymbols.1.) Matter – anything that has mass and occupies space.- Matter comes in three MAIN forms – liquids, gases, and solids- Different types of matter includes elements, compounds, atoms and molecules. Element – a substance that cannot be changed bychemical reaction into twoor more new substances. The building blocks of all substances. On thePeriodic Table, they are numbered in order of increasing complexitybeginning with Hydrogen.94 elements are known to occur in nature. Commonelements include gold, neon and iron. Compound – a substance that contains two or moreelements.Unlike elements,compounds can be decomposed chemically into simpler compounds and/orelements. Examples of compounds are salt (NaCl2), sugar(C12H22O11) and water (H2O). Atom – the smallest particle of an element thatembodies the chemicalproperties of that element.Every atom contains an extremely small, extremelydense nucleus (the nucleus is the center of an atom). Nearly all of the mass ofan atom is concentrated in the nucleus.The nucleus is surrounded by a muchlarger volume of nearly empty space that makes up the rest of the atom.Examples of atoms: H, O, Fl, N, and C (Be familiar with these elements onthe periodic table!)~Atomic Theory~All matter is composed of atomsAll atoms of a particular element have thesame chemical propertiesCompounds are formed by the chemicalcombination of two or more different kinds ofatomsA chemical reaction involves joining,separating or rearranging atoms Molecule – a collection of atoms connected by bonds. They are the smallestpart of a compound. Examples of compounds are N2, H2, and Br2 (Nitrogen,Hydrogen and Bromine)~The difference between molecules and compounds~ A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements. All compounds are molecules but not all molecules are compounds.Platinum: Element/ Platinum: Molecule/ Platinum: Atom2.) Chemical symbol – the one or two letter abbreviation for the name of an element.Examples: H, O, C, Fe, Cu, Ar(*NOTE: Not all symbols reflect their elements. Some symbols reflect their Latin names, such as Au, Ag, Fe, and Cu – Gold, Silver, Iron and Copper)3.) Chemical formula– symbols of different kinds ofatoms written together with subscripts showing how many atoms of each kind are in a molecule. Examples: H2O, CO2, MgCl2, N2, O2The Periodic TableA table of the chemical elements arranged in order of atomic number, usually in rows, so thatelements with similar atomic structure (and hence similar chemical properties) appear invertical columns.The periodic table is composed of solid, liquid and gaseous matter primarily known asmetals, metalloids and gases:1.) Metals – Makes up the largest portion of the periodic table. Good conductors of electricity; lustrous (shiny i.e. platinum); ductile (can be drawn into wires i.e. tin); malleable (can be rolled into sheets i.e. aluminum); solids at room temperature, EXCEPT for Mercury (Hg). Think about thermometers – the typical red liquid is Mercury, but it is not a solid when it is in a room.2.) Nonmetals – Usually do not conduct electricity; most exist as gases (at room temperature)– bromine is a liquid and carbon, phosphorus, sulfur, selenium, andiodine are brittle solids3.) Metalloids – Lustrous and less conductive than metals(semiconductors);brittle The Periodic Table is organized by atomic number. The atomic number is the number of protons each element has. The number of protons decides each element. For example, no other element has atomic number 1, except for Hydrogen. The columns of the periodic table are called groups or families. The reason why they are called groups are because elements tend to have the same properties as you go down the columns, thus you can “group” them together or consider them “family” The rows on the periodic table are called periods. Starting from the left side, the first group is consists of the alkali metals (thesewill all violently react with water). The next group directly adjacent from them is called the alkaline metals. The transition metals are located in the center of the table, next to the alkaline metals. The last 3 groups are the chalcogens, halogens and noble gases. These groups are the most important and must be