Chemistry Do Now 10-18-17 Directions: Take out your Do Now sheet and answer each question based on yesterday’s slime lab. 1) What were the 3 ingredients used to make your slime? 2) What effect did the borax have on the glue and water? 3) Describe the type of interaction between the Elmer’s glue, water and borax? Were the intermolecular forces between the glue, water and borax stronger or weaker than each of their intramolecular forces? Why or why not? 4) What did you notice as you added more borax solution to the glue? Why do you think you got this result?

Chemistry Do Now 10-18-17 KEY 1) What were the 3 ingredients used to make your slime? Glue, food coloring and borax solution 2) What effect did the borax have on the glue and water? It make the glue become more solid, almost rubber-like. 3) Describe the type of interaction between the Elmer’s glue, water and borax? Were the intermolecular forces between the glue, water and borax stronger or weaker than each of their intramolecular forces? Why or why not? The borax seemed to get between the glue and water molecules, but the intermolecular forces within the glue were still stronger than the intramolecular forces between the glue molecules because the chemical bonds holding the glue together was stronger than the attractive forces between the glue and the borax solution. 4) What did you notice as you added more borax solution to the glue? Why do you think you got this result? I noticed the more borax solution I added, the more solid the glue/water solution became because the borax was attracted to the glue and water.

Objective Students will know how intermolecular forces (IMFs) between atoms that share pairs of electrons (covalent bonding) determine the properties of the molecule by performing a close read on forming polymers, answer text-dependent questions based on the article, take notes on covalent bonding and answering . Mastery Level: 25 pts. on close read annotations, 4/6 (67%) on TDQs, and ¾ on exit ticket questions

Homework - Copy Research any five molecules that are held together by covalent bonds. Compare and contrast them.

Engage Show the students the YouTube video “Covalent Bonding” Source: https://www.youtube.com/watch?v=LkAyk Ov1foc

Explore Students will perform a close read on the Slime article. As the students read the text, they will annotate using the symbols posted on charts in the classroom. Following their annotations, the students will answer 6 scaffolded text- dependent questions. 1) What is the main idea of the article? 2) Cite 3 statements from the article to support your main idea. 3) The author uses two illustrations in the article. How does the author use the pictures to help the reader understand polymerization? 4) What is the author’s purpose for writing this article: entertainment, information or persuasion? How do you know? 5) How is the text organized to help build your understanding of the main idea? 6) Now that you have read the article, explain what the author failed to discuss? Explain why this topic should have been discussed in the article. Where should this topic have been mentioned in the article? Why?

Explain intermolecular forces (covalent bonding) Students will take notes. Explain intermolecular forces (covalent bonding)

Covalent Bonding Unit III: Combining Atoms October 18, 2017

Review of Ionic Bonding We learned about electrons being transferred (“given up” or “stolen away”). This type of “tug of war” between a METAL and NONMETAL is called an IONIC BOND, which results in a SALT being formed

Molecular Compounds Now, you will learn about another type of bond in which electrons are shared Covalent Bonds are atoms held together by SHARING electrons between NONMETALS

Salt versus Molecules A metal cation and nonmetal anion are joined together by an ionic bond called SALT A group of atoms joined together by a covalent bond is called a MOLECULE A Compound is a group of two or more elements bonded together (Ionic or Covalent).

Ionic vs Covalent

Monatomic vs. Diatomic Molecules Most molecules can be monatomic or diatomic Diatomic Molecule is a molecule consisting of two atoms There are 7 diatomic molecules (SUPER 7) – N2, O2, F2, Cl2, Br2, I2, H2 You can also remember them as: H2O2F2Br2I2N2Cl2

Properties of Molecular Compounds Liquids or gases at room temperature Lower Melting Points than Ionic Compounds (which means that they are weaker than ionic)

Molecular Formulas The Molecular Formula is the formula of a molecular compound It shows how many atoms of each element a molecule contains Example H2O contains 3 atoms (2 atoms of H, 1 atom of O) C2H6 contains 8 atoms (2 atoms of C, 6 atoms of H)

Practice How many atoms total and of each do the following molecular compounds contain? H2 CO CO2 NH3 C2H6O

Practice: True or False All molecular compounds are composed of atoms of two or more elements. All compounds are molecules. Molecular compounds are composed of two or more nonmetals. Atoms in molecular compounds exchange electrons. Molecular compounds have higher melting and boiling points than ionic compounds.

Ionic versus Covalent IONIC COVALENT Bonded Name Salt Molecule Bonding Type Transfer e- Share e- Types of Elements Metal & Nonmetal Nonmetals Physical State Solid Solid, Liquid, or Gas Melting Point High (above 300ºC) Low (below 300 ºC) Solubility Dissolves in Water Varies Conductivity Good Poor

Covalent Bonding Remember that ionic compounds transfer electrons in order to attain a noble gas electron configuration Covalent compounds form by sharing electrons to attain a noble gas electron configuration Regardless of the type of bond, the Octet Rule still must be obeyed (8 valence electrons)

Single Covalent Bond A Single Covalent Bond consists of two atoms held together by sharing 1 pair of electrons (2 e-)

Single Covalent Bond A Single Covalent Bond consists of two atoms held together by sharing 1 pair of electrons (2 e-)

Double Covalent Bonds Sometimes atoms attain noble gas configuration by sharing 2 or 3 pairs of electrons A Double Covalent Bond is a bond that involves 2 shared pairs of electrons (4 e-)

Triple Covalent Bond A Triple Covalent Bond is a bond that involves 3 shared pairs of electrons (6 e-)

Covalent Bonds

Extend 1) Explain how a single covalent bond is formed, double covalent bond, and a triple covalent bond. 2) Draw a Venn diagram comparing and contrasting a nonpolar and polar covalent bond.

Evaluate Exit Ticket Questions on IMF 1) What are the differences between an ionic and a covalent bond? 2) What is meant by unequal sharing of electrons? How does this result in the formation of a polar molecule? 3) What is meant by equal sharing of electrons? How does this result in the formation of a nonpolar molecule? 4) Which type of bond, ionic or covalent, has the higher intermolecular force? How do you know? SKILL MASTERY LEVELS (Based on 100 maximum points): 4/4 correct (100 points): SKILL EXCEPTIONALLY MASTERED 3/4 correct (75 points): SKILL ADEQUATELY MASTERED <3/4 correct (<75 points): SKILL NOT MASTERED