Chapter 2 - Summary General Chemistry PDF

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Elements and Compounds Book Chapter 2 OWL Extras Subatomic particles~ what makes up atoms: protons, neutrons, electrons Proton~ relative charge +1, mass of 1.672722 X 10-24 Neutron~ no electrical charge, mass of 1.674927 X 10-24 Electron~ relative charge of -1, mass of 9.109383 X 10-27 Atomic nucleus~ small region of high density at the center of an atom Atomic mass unit (u)~ 1/12 the mass of a carbon 12 atom Both protons and neutrons have approximately 1 u in mass Ion~ atom with an unequal number of protons and electrons Cation~ when an atom carries more protons than electrons Anion~ when an atom carries more electrons than protons Atomic number (Z)~ the number of protons in the nucleus Mass number (A)~ the number of protons and neutrons in the nucleus of an atom Atomic/Nuclear symbol~ one or two letter symbol that represents the element Isotopes~ atoms that have the same atomic number but different mass numbers Atomic weight~ average mass of all naturally occurring isotopes of that element Percent abundance~ percentage of the atoms of a natural sample of the pure element Periodic table of elements~ table of elements, atomic weight, mass and group of elements Groups~ elements arranged in vertical columns Periods ~ elements arranged in horizontal columns Alkali metals~ groups 1A elements, shiny solids that react vigorously with air, water, halogens Halogens~ group 7A elements Alkaline earth metals~ group 2A elements, react with water to form alkaline solutions Noble gases~ group 8A, least reactive elements in the periodic table Main-group elements~ elements in group A Transition metals~ elements in group B Lanthanides~ period 6 on the periodic table Actinides~ period 7 on the periodic table Metals~ elements on the left side of the periodic table Nonmetals~ elements on the right side of the periodic table Metalloids/semimetals~ elements that interface the metals and nonmetals Allotropes~ same elements that differ in their physical and chemical properties Covalent compounds~ atoms of different elements held together by covalent bonds Molecular covalent compound~ atoms held together by molecular bonds Network covalent compound~ 3-dimensional network of atoms held together by covalent bonds Molecular formula~ symbol and subscript of atoms (there is no number for 1)

Empirical formula~ simplest whole-number ratio of elements in a compound Structural formula~ visual linkage of all atoms in molecule Condensed structural formula~ list of all atoms present in structural formula Wedge-and-dash model~ 2-dimensional representation of a 3-dimensional structure that can be drawn on paper Ball-and-stick model~ atoms as colored spheres connected by sticks that represent covalent bonds Space-filling model~ interpenetrating spheres that represent the relative amount of space occupied by each atom in a molecule Binary nonmetals~ type of covalent compound, only two elements, named after rules 1. First word is the name of the first element in the compound. a. If more than one, use a prefix to indicate number of atoms in formula 2. Second word is the name of the second element changed with -ide 3. Combine the first and second words of the compound name Hydrocarbons~ binary nonmetal compounds containing only carbon and hydrogen Inorganic acids~ type of covalent compound, produce H+ when dissolved in water and are compounds that contain hydrogen and one or more nonmetal Oxoacids~ named according to the number of oxygen atoms in a formula Ionic compounds~ ions that carry a particular charge Monoatomic ion~ when a single atom gains or loses one or more electrons *writing tip, number before charge Polyatomic ions~ groups of covalently bonded atoms that carry an overall positive or negative charge ***!!!!! MEMORIZE THE LIST Rules for naming ionic compounds and ions 1. Monoatomic cations a. Main group monoatomic cation i. Name followed by ion b. Transition metal i. Element name followed by the cation charge in Roman numerals with parentheses and ion 2. Monoatomic anions a. Monoatomic anion i. Element name changed to include -ide 3. Polyatomic ions a. Must be memorized 4. Ionic compounds a. Name followed by anion name i. Drop ion because compound doesn’t have a charge ii. No prefixes because number present Identifying covalent and ionic compounds

● Covalent compounds ○ Contain only nonmetals ○ Are named using prefixes to indicate the number of each element in a formula ● Ionic compounds ○ Contain monoatomic and/or polyatomic ions ○ Usually contain metals and nonmetals but can also contain only nonmetals ○ Are never named using prefixes ○ Are sometimes named with the cation charge in Roman numerals within parentheses...