In this lesson we will take a look at the 3-Dimensional world we live in. Look at the image below. You will see two points.

A line has only one dimension --length. The line has no endpoints and extends forever in both directions. That is why when a line is drawn, we see arrows at both ends. On the other hand when we draw a line segment on a piece of paper it has endpoints.

**Question 1:** How many endpoints
does a line segment have?

The line, ray and line segment are all examples of 1-Dimensional objects since they only have length.

**Review measuring length of a line segment using Jsmol **

-------------->spin on -------->-
spin off

2: What is the length of line segment CD in Angstroms to the nearest hudredth?

- Activity 1: Measuring length and distance at the molecular level
- Activity 2: Geometry-of-1-Dimension
- Activity 3: Geometry of 2- Dimensions
- Activity 4: Geometry of 3-Dimensions
- Activity 5: Introduction to Molecular Modeling using Jsmol
- Activity 6: The Geometry of Crystals
- Activity 7: Summary Sheet by Students
- Activity 8: What is the Geometry of the Methane Molecule
- Activity 9: Geometry of the Crystal Structure of Ice
- Activity10:Geometry of the Benzene Molecule