Periodic Properties of the Elements and Molecules and Compounds
Periodic Properties of the Elements and Molecules and Compounds CHEM 101
Popular in Structural Chemistry, with Application to Chemistry of the Elements
Popular in Science
This 5 page Class Notes was uploaded by Piper Daniels on Thursday September 24, 2015. The Class Notes belongs to CHEM 101 at University of Alabama - Tuscaloosa taught by Mrs. Leung in Summer 2015. Since its upload, it has received 18 views. For similar materials see Structural Chemistry, with Application to Chemistry of the Elements in Science at University of Alabama - Tuscaloosa.
Reviews for Periodic Properties of the Elements and Molecules and Compounds
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/24/15
Chapter 4 Exam 2 CH 101003 Monday October 5th 5pm615 pm Shelby 1004 Ch 45 Need Act Card CWID Scientific Calculator Pencil Ionization Energy 1 Ionization Energy IE the energy required to remove an electron from an atom or ion in its gaseous state a IE positive value i endothermic process ii system absorbs energy b Valence electrons are the easiest electrons to remove because they are the furthest from the nucleus 2 First ionization energy IE1 energy required to remove the first electron Ex Nag lE1 gt 1e39 Nag lE1 Na 496 kJmol 3 Second ionization energy lE2 energy required to remove the second electron a Not two electrons Ex Nag lE2 gt 1e39 Na2g lE2 Na 4560 kJmol 4 E1ltE2ltE3 Na Mai e 11 11 e 11 1 equot 1111 1111 F larger radiua larger retie emaller rediuelieuter ehell eleetrne are eleee he the nueleue requiree mere energy rte rernea e an eleetr enjl 5 Trends a Downagroup i principal number n increases valence electrons ii atomic radius increases iii decreases in ionization energy require less energy to remove valence electrons b Across a period left to right i Zeff increases feel a larger positive charge ii atomic radius decreases iii increases in ionization energy requires more energy to remove valence electrons 3 quot 39Ez i if a IEEiNEl45vEn Writtil 1 522 SEE ESE 1 EE EEEEFJE My 19 3952 lE39 MQE IEEEMQJF145 ltdfnqol i 1stapt2p gpi mag gzp agg Electron Affinity 1 Electron Affinity EA is the energy required to add an electron to an atom in the gaseous state EA negative value a exothermic process Clg 1e39 gt Clg EA Trends EA Group 1A Only a Down group 1A i increase EA less exothermic more positive energy less favorable to add electrons ii n increasing Trend EA period a Across a period left to right i Zeff increases ii more exothermic more negative more favorable to add electrons IE Increases II E Increases Nitrcgen has a hiher IE because principal shell is mare impcrtant than ZEff Chapter 5 Compounds 1 Atoms the smallest particle still characterizing a chemical element 2 Molecules anything that has more than one atom that is joined through bonds ex H20 H2 3 Compounds molecules that have more than one element and can be decomposed to elements ex H20 not H2 because it does not have more than one element Chemical Formula 1 Chemical Formula specifies the elements in a molecule and their ratio in one molecule ex HNO3 hydrogen nitrogen oxygen 11 3 ex NH4ZSO4 nitrogen hydrogen sulfur oxygen 281 4 a in one molecule of ammonium sulfate there are actually two ammoniums this means that you have to multiply the subscripts in the inside of the parentheses by the number outside of the parentheses Categories 1 Molecular Formula MF gives the actual number of atoms for each element in one molecule of a compound ex hydrogen peroxide MF H202 2H 20 atoms 2 Empirical Formula EF lowest whole number ratio of elements in a compound ex hydrogen peroxide EF HO a we divided both subscripts by 2 3 Structural Formula use lines to represent bonds in a molecule ex hydrogen peroxide a shows the number of each atom b shows the connectivity of atoms Lewis ModelsStructures 1 Lewiselectron dots a dots represent valence electrons i Main group GpA ii Transition Elements outermost shell incomplete d and f blocks b chemical symbols represent core electrons exCandO ll I39ll E 9 i I 1322372253E c always pair electrons together in groups of 2 Lewis Structurefor molecules 1 Valence electrons 2 Connectivity 3 Bonding electrons shared between two atoms 4 Nonbonding electronslone pairs electrons belong to only one atom in the molecule ex H20 in HIEIH a the two above and below the O are lone pairs b the left and right pairs are bonding electrons 5 Bonding a 2 electrons shared single bond one line in place of bonding electron b 4 electrons shared double bond two lines in place of bonding electrons c 6 electrons shared triple bond three lines in place of bonding electrons Lewis Structure 1 Chemical bonds atoms form bonds to achieve a noble gas electron configuration a Noble gases8 valence electrons octet b He 2 valence electrons duet 2 lonic Bonds transfer electrons 3 Covalent bonds share electrons Molecular Compounds 1 Covalent bonds interaction between two nonmetals or a nonmetal and a metalloid by sharing electrons 2 Sharing electrons putting electrons in between two nuclei stabilizes the atoms making a lower potential energy 3 Molecular compounds those with covalent bonds ex water hydrogen is a nonmetal oxygen is a nonmetal this means that they are covalent bonds Ionic Compounds 1 lonic bonds electrons being transferred between a metal and a nonmetal a Metal always going to lose electrons cations b Nonmetal always gains electrons anions 2 The exact number of electrons is dependent on the number in their shell ex Na 1e39 1s22s22p63s1 Cl 17 e39s 1s22s22p63s23p5 a metal a nonmetal b loses electrons b gains electrons c Na Ne c CI39 Ar d Na Cl39 interaction is an electrostatic interaction 3 There is no such thing as a bond between an anion and cation in an ionic bond 4 lonic bonds are not directional no physical bond between one sodium ion and one chlorine ion a Each ion is surrounded by its counterion 5 Formula Unit describes the smallest whole number ratio of atoms in ionic compounds
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'