1. Activity 17: Modeling Molecules

2. Introduction Read B-31 Challenge:
How do atoms combine to form molecules?
Initial Ideas

3. Chemical Bond
The electrical attraction between two different atoms (elements) that forms a molecule (compound).

4. Molecular Models What is an atom? What is an element?
The smallest building block of matter
What is an element?
A molecule composed of only one type of atom

5. Prior Knowledge

6. Protons

7. Neutrons

8. Electrons

9. Structure of the Atom

10. Molecular Model Sets A complete set contains:
4 elements, 64 atoms
Black: Carbon (18)
White: Hydrogen (32)
Blue: Nitrogen (4)
Red: Oxygen (14)
54 white bonds
Colors do not correspond to actual physical properties of the atoms

11. Molecular Model Sets
The spherical center of each model represents the center of the atom
Nucleus
The protruding “sticks” represent the bonding sites
Electrons
NOT TO SCALE!!!!!

12. Procedure Steps 1-3 Together Steps 5-10 Guided
Elements are written using the capitalized chemical symbols shown on the periodic table.
The number of atoms in one molecule is noted by writing the number as subscript after the atomic symbol.
When there is one atom in a molecule, such as the one oxygen molecule in H2O, the one is not written, it is implied.
Steps 5-10 Guided
Steps In Your Group

13. Discussion
What information do the models show about atoms, elements, and molecules?
Each model atom shows the number of bonds that a particular atom can make.
Nitrogen - 3 bonds
Hydrogen - 1 bond
NH3
From this information you can predict the molecules the atom can form and the formulas of compounds that will result.