Please turn in: Self-Reflection #7 Lab Rubrics for Solution to Solutions

Ionization versus Dissociation Energy is required to remove a negative charge from a positive charge. (because you need energy to overcome the force of attraction, opposites attract). Ionization: the process of removing an electron from an atom (i.e., separating positive and negative charges) Na 0 + IENa 1+ + e - 11e- 11p+ 10e- 11p+ + e - + IE Forming a sodium ion from a neutral Na atom requires energy. The electron on the right can transfer to another particle

Ionization versus Dissociation Dissociation: the process of separating positive and negative ions from a crystal lattice. (i.e., separating positive and negative charges) NaCl (s) Na 1+ (aq) + Cl - (aq) Symbol representation of dissociation. Sodium chloride (solid NaCl) dissociates in water to form sodium ions (Na + ) and Chloride (Cl - ) in an aqueous solution.

Ionization versus Dissociation Ionization and Dissociation are both processes where positive and negative charges are being separated. What’s the difference??? Ionization: forces WITHIN the particle Separation of protons and electrons Dissociation: forces BETWEEN particles When the ions are separated in the crystal lattice What’s the crystal lattice?

Ionization versus Dissociation IonizationDissociation Depends on forces inside an atom (between electrons and protons) Ionization energy is the energy required to remove an electron from a neutral atom Depends on forces between atoms (between positive and negative ions) Occurs because of solvation. Ions separate in solution

Trends in Ionization Energy Ionization Energy Decreases Ionization Energy Increases Lowest I.E. Highest I.E.

Ionization versus Dissociation Ionization energy is like “electron greed”. How badly does the atom what to hold on to its electron? Lower I.E. means it is easier (takes less energy) to remove an electron from the atom and create an ion. Higher I.E. means it is more difficult (takes more energy) to remove and electron from the atom and create an ion.

Ionization versus Dissociation P&P #4: Make a Venn diagram to illustrate the similarities and differences between ionization and dissociation.

P&P #4 p. 130

Ionization versus Dissociation Ionization energy can help us to predict the type of bond that will form between two atoms. HOW??? Bond type depends on differences in electrical properties. Let’s try to find a trend…

Ionization versus Dissociation P&P #5a: Predict the relative ionization energies associated with ionic, covalent, and polar bonds. Ionic bonds form when particles have opposite net charges (IE energy is High) Example: Na + + Cl – One particle loses an electron Which one? The ionization energies of 2 atoms in an Ionic solid are very far apart (just like their location on the Periodic Table)

Ionization versus Dissociation P&P #5a: Predict the relative ionization energies associated with ionic, covalent, and polar bonds. Covalent bonds have the same tendency to attract electrons so they act more neutral (IE energy is low) Example: CO 2 Why? The atoms involved in bond have the same tendency to attract electrons Look at the locations of Carbon and Oxygen Polar bonds are between ionic and covalent H 2 0

Ionization versus Dissociation P&P #5b: Predict what type of bonding (Covalent, ionic, or polar) occurs between hydrogen atoms in the elemental compound H 2 Hydrogen gas has two atoms that are the same. Ionization energies are equal If the energy is equal, than any electrons involved in bonding will be shared equally= COVEALNET

Ionization versus Dissociation P&P #5c: Draw a series of molecular level sketches to show whether hydrogen gas H 2 is highly soluble in water. H H O No interaction H H No dipole Hydrogen gas (H2) molecule interacting with water. Hydrogen’s low solubility in water is due to hydrogen being non-polar and water being polar

Charge Those Particles – Day 3 Sharing Electrons p. 125

Part III: Sharing Electrons Read Intro p. 131 Read “Electronegativity” p. 132 Take notes! Make a Venn Diagram to compare and contrast electronegativity and ionization.

Entry Task Represent the Ionization of Potassium (K): Represent the Dissociation of Magnesium Chloride (MgCl 2 )

Entry Task Would you expect the Ionization Energy of Chlorine (Cl) to be higher or lower than the Ionization Energy of Radium (Ra). Explain.

Charge those Particles – Day 3 Learning Target: I can describe chemical bonding between atoms.

Electronegativity Covalent bonds form when atoms have similar electrical properties. Ionization energy is one way to quantify those electrical properties Electronegativity is another way to quantify electrical properties.

Electronegativity Electronegativity is the ability of an atom to attract electrons. The higher the electronegativity, the more strength the atom has to pull electrons toward itself.

Electronegativity Electronegativity is the ability of an atom to attract electrons. The electronegativity scale was devised by Linus Pauling. It is an arbitrary scale with Fluorine (the most electronegative element) having a value of 4. All other electronegativities are assigned relative to Fluorine. Why Fluorine??

Electronegativity Differences in electronegativity between two atoms can tell you what type of bond will form between those atoms. If two atoms have similar electronegativities, neither is stronger than the other. They will share electrons equally… this is a covalent bond.

Electronegativity If two atoms have somewhat different electronegativities, one atom is slightly stronger than the other. They will share electrons UNequally… this is a polar covalent bond. They are still sharing electrons, but the electrons spend more time around the more electronegative atom (giving it a slight negative charge), and less time around the less electronegative atom (giving it a slight positive charge) creating a dipole.

Electronegativity If two atoms have very different electronegativities, one atom is much stronger than the other. The stronger atom will take the electron(s) from the other atom. This is an ionic bond. The atom that takes the electron(s) becomes a negative ion. The atom that gives up the electron(s) becomes a positive ion. The ions are attracted to each other and form a crystal lattice.

Predicting types of bonds… Type of bondNon-polar covalent Polar covalentionic Electronegativity difference < – 2.1> 2.1 ElectronsShared EquallyShared UnequallyTransferred (not shared) ExampleO 2 or H 2 or CO 2 H2OH2ONaCl TermsCovalent moleculePolar molecule (with a dipole) Ionic compound (i.e., salts)

Electronegativity What trends do you see in electronegativity? What type of bonds form when atoms from opposite sides of the periodic table for a compound?

Trends in Electronegativity Electronegativity Increases Lowest EN. Highest EN.

Questions P&P #1 p. 131: Make a Venn diagram to compare and contrast Ionization and Electronegativity P&P #3a p. 134: Make a diagram to show how each pair of atoms listed below shares or transfers electrons and determine the type of bond: Hydrogen – Oxygen in water Carbon – Oxygen in CO 2 Potassium – fluorine in KF Carbon – Hydrogen in CH 4 Bromine – Bromine in Br 2

Reflect & Connect Complete R&C #1-3 p. 135 & 139 Read “Water works” p. 136 & take notes Read “Mysterious Metals” p. 138 & take notes

Water Works Mysterious Metals Discuss R&C

Reflect and Connect

MINI-LAB

For this activity you will need: 1 worksheet packet for each student 1 atom skeleton for each student 1 valence skeleton page per student (they will need to cut these out and work in pairs to show bonding) 20 skittles per student (all same color) (partners should have different colors to help show electron sharing/transfer)

Balance Chemical Equations re=youtu.be re=youtu.be WKST # 1 WKST #2

Review Videos Bohr: Ionization: Electronegativity: Covalent Bonding: Polar: Ionic: EOy2mw&feature=youtu.behttp:// EOy2mw&feature=youtu.be