BELLRINGER
What is the chemical formula for water? Draw what one molecule of water looks like and draw what 5 molecules of water looks like.
1 Molecule H
2
0 5 Molecules H
2
0

Pictures of the Mind

Macroscopic vs. Microscopic
 We live in a macroscopic world.
 Atoms and elements exist in a microscopic world.
 How do atoms in tin foil look or what do atoms in water look like?
 Create models or representations to help us understand things.

Anatomy Models

Architecture Models

Biology Models

Model Models?

Chemistry Models

Sample Problem # 1
• Draw a model of a homogenous mixture composed of three different gaseous elements.
– Homogenous: Uniform throughout (compound should be intermingled and evenly distributed)
– Can the atoms of the elements exist as diatomic molecules?

Answer

Sample Problem # 2
• What kind of matter does the following model represent? Explain your answer!

Answer
• This model represents a heterogenous mixture of two molecular substances, each of which consists of two types of atoms.

Sample Problem # 3
• Draw a model of a container of each of the following samples of matter.
– Table 1 and Table 7: Mixture of gaseous elements X and Z.
– Table 2 and Table 6: A two-atom compound of X and
Z.
– Table 3 and Table 5: A four atom compound of X and Z
– Table 4: A solution composed of a solvent that is a two-atom compound of L and R, and a solute that is a compound composed of two atoms of element D and one atom of element T.

Table 1 & Table 7

Table 2 & Table 6

Table 3 & Table 5

Table 4

Sample Problem # 4
• Answer Question #4 on your handout!

Sample Problem # 5
• The element Iodine (I) has a greater density in its solid state than its gaseous state. Draw models that depict and account for this difference at the particulate (really small!) scale. Iodine normally exists as a two-atom molecule.

Answer # 5

Sample Problem # 5
• A chemistry student at Riverwood High School was asked to draw a model of a mixture composed of an element and a compound.
Comment on the usefulness of the students drawing.

Answer # 6

Sample Problem # 7
Finish Up Sample Problem # 7 in your group.
Remember to turn the packet in before you leave.
If you didn’t finish it then it is homework.