Covalent and Ionic Bonding Chemical Bonding Covalent and Ionic Bonding

Compound Review Compound: a chemical combination of two or more elements Why do elements chemically combine? They want to achieve full energy levels Full energy level = stability Elements will move electrons for them to be satisfied

How do the electrons move? Two ways: Transferring electrons between two atoms One atom is close to having a full level, while the other is close to emptying a level Electrons are transferred from the almost empty atom to the almost full atom to make both satisfied Sharing electrons between two atoms Both atoms are close to having full levels Electrons are shared back and forth between two atoms to make both feel satisfied

How do the electrons move? Ionic Bonding Transferring electrons between two atoms One atom is close to having a full level, while the other is close to emptying a level Electrons are transferred from the almost empty atom to the almost full atom to make both satisfied Covalent Bonding Sharing electrons between two atoms Both atoms are close to having full levels Electrons are shared back and forth between two atoms to make both feel satisfied

Ionic Bonding Ionic Bond: a bond where the bonding electrons are transferred between two atoms Typically occurs between a non-metallic and a metallic element These are elements on opposite sides of the PT The metallic elements are close to emptying a level The non-metals are close to having a full level The electron is transferred from the metal to the non-metal

Characteristics of Ionic Bonds Ionic molecules are bound by charge The transfer of electrons creates opposite charges The atom that gains electrons is negative The atom that loses electrons is positive Ionic bonds form crystals There is a lot of attraction between one set of bonding atoms and another The attraction tends to create solids

Ions

Binary Ionic Nomenclature Positive atom first, negative second Charges must add up to zero NO PREFIXES used in the written name Ending of second element switched to “-ide”

Examples Magnesium bonds with bromine Chlorine bonds with potassium Which comes first? ClK or KCl How do we write the name? Potassium chloride Magnesium bonds with bromine Which comes first? MgBr2 or Br2Mg How do we write the name? Magnesium bromide

Transition Metals Transition metals are from Group 3 up to the dividing line that cuts through the “p” section Remember that these metals have electrons in overlapping energy levels Because of this overlap, the atom is often trying to fill two different levels instead of just one This means that transition metals will often have more than one possible charge

Transition Metals (continued) In the written name of a compound, the transition metals will have a Roman numeral that follows its name The Roman numeral designates the charge of the transition metal The Roman numeral does not need to be written in the molecular formula of the compound

Transition Metal Examples Iron with a +3 charge bonds with chlorine Molecular formula? FeCl3 How do we write the name? Iron (III) chloride Copper with a +1 charge bonds with oxygen Molecular Formula? Cu2O How do we write the name? Copper (I) oxide

Polyatomic Ions “Poly-” means many Polyatomic ion: an ion formed of more than one type of element These types of ions are typically unsatisfied covalent bonds Listed on back of PT

Polyatomic Ions (continued) Polyatomic ions have names that typically end in “- ate” or “-ite” When writing the molecular formula, you still make the charges neutral If a polyatomic ion needs to be multiplied to make the charges neutral, it should be in parentheses When writing the name, do not change the ending of the polyatomic ion; just use it as listed

Polyatomic Ion Examples Calcium bonds with nitrate Molecular formula? Ca(NO3)2 How do we write the name? Calcium nitrate Iron with a +3 charge bonds with carbonate Molecular Formula? Fe2(CO3)3 How do we write the name? Iron (III) carbonate

Ionic Practice TiI4 Na2CO3 NaOH FeCl2 FeCl3 Li3PO4 Lead (II) Sulfite Beryllium Chloride Gallium Nitride

Covalent Bond Covalent Bond: a bond where the bonding electrons are shared between two atoms Typically occurs between two non-metallic elements These are elements to the right side of the PT These elements are close to having full energy levels

Covalent Bonding

Covalent Molecules Covalent molecules are bound by proximity The molecules must be close to each other to share the electron(s) Covalent bonds form individual molecules

Lewis Structures Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons”

Covalent Bond Cl2 Chlorine will form a covalent bond with itself.

Cl Cl

Cl Cl

Cl Cl

Draw these bonds H2 F2 HF H2O NH3 CH4 I2 NF3

Covalent Nomenclature Nomenclature: a system of naming Lower electronegative atom first, highest second Prefixes used in front of each element to show quantity of atoms that are sharing Ending of second element switched to “-ide”

Covalent Nomenclature One Mono- Six Hexa- Two Di- Seven Hepta- Three Tri- Eight Octa- Four Tetra- Nine Nona- Five Penta- Ten Deca-

Examples Example of a molecular comp: CO2 CO CCl4 Carbon tetrabromide

Practice PCl5 SF6 carbon trichloride N2O disulfur hexoxide NO2 nitrogen triiodide

Practice CCl4 nitrogen triiodide C2H6 DOUBLE BOND SiO2

Prompt Tell me about something that’s good in your life right now. It could be something at home, something related to school, or anything else that makes you happy.