Unit 1: Matter Day 33 Focus: Molecule Models 10-16-17 1. ***Place your homework worksheet “How to Count Atoms/Counting Atoms” in the box on the lab table. 2. Science Starter: Copy the question. Choose an answer and write the entire answer in your response box. Q - How does the zig-zag line on the periodic table help indicate properties of elements?  Elements located on the left of the zig-zag line are liquids at room temperature. Elements located on the right of the zig-zag line are liquids at room temperature. Elements located on the left of the zig-zag line are good conductors of heat and electricity.

Plan for Today: 6th Period only– Notes on chemical formulas and equations All classes: “Modeling Molecules” lab Review Counting Atoms

Homework “Find the Image” counting atoms activity

Essential Question: How do atoms bond to make molecules?

Chemical Formulas Copy these 3 examples. Def. Chemical formula is a combination of chemical symbols and numbers to represent a substance.It shows how many atoms of each kind of element are present in a molecule. Subscript: a number written to the lower right of a chemical symbol. It tells how many atoms of that element are present. Copy these 3 examples.

chemical Equations Def. Use chemical symbols and formulas to describe a chemical reaction. Ex: Copy this Chemical equation. C and O2 are the reactants. CO2 is the product. yields

H C O N Let’s start our “Modeling Molecules” activity. Draw a Lewis Structure (dot diagram) for each of the elements at the top of the “Modeling Molecules” sheet.. Fill in the # of electrons needed to fill the atom’s outer shell. H C O N Needs ___ elec. Needs ___ elec. Needs ___ elec. Needs ___ elec.

Let’s read about “Modeling Molecules”. We will make the molecules together. You will then draw the molecules and count the total number of atoms in each molecule. Please write the following: Hydrogen - white Carbon - black Oxygen - red Nitrogen - blue

Molecule #1 1. Build a molecule of water with 2 hydrogen and 1 oxygen. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula. 3. Pull the model apart.

Molecule #2 1. Build a molecule of hydrogen and carbon. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula.

Molecule #3 1. Build a molecule of hydrogen and nitrogen. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula.

Molecule #4 1. Build a molecule of two oxygen atoms. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula.

Molecule #5 1. Build a molecule of two hydrogen atoms. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula.

Molecule #6 1. Build a molecule of two nitrogen atoms. Use the white bonds (tubes) to make the connections that represent chemical bonds. 2. Write the total number of atoms and the chemical formula. 3. Pull the models apart.

Molecule #7-10 Build and draw 4 more molecules according to these rules: a. Molecules must contain between 2 and 5 atoms. b. All bonding sites (protruding “sticks”) of an atom must be connected to those of another atom.

Molecule #11-12 Build and draw 2 more molecules according to this rule: All bonding sites (protruding “sticks”) of an atom must be connected to those of another atom. *Can you build a glucose molecule – C6H12O6 ?

Which of these 3 terms (element, molecule, compound) apply to the following? If a molecule, how many? O2 2H2O 4H2

Review quiz?

Let’s see how you did on the “Practice Counting Atoms Worksheet”.