Lesson 5

Lesson Objectives...

• Analyze and interpret the data for common gases to look for patterns that could be used to identify an unknown gas by its characteristic properties. 

• Apply scientific reasoning based on patterns in the densities for a known set of gases to explain how either of two different possible outcomes from a future investigation could help us narrow down the sub-set of candidate substances from what could be in the unknown gas from the bath bomb. 

• Construct, use, and present an oral and written argument for an explanation that the gas in the bubbles from the bath bomb can be narrowed down to only three possible substances (out of ten of the most common ones in the air) supported by the patterns in the results from density and flammability tests and data on their properties and the use of related key model idea.

Resources for Lesson 5...

Properties of Some Common Gases

Use the data table to identify properties of common gases.  

Flammability of Air and Helium

Watch the video to determine the flammability of air and helium.

Flammability of the Bath Bomb Gas

Watch the video to determine if the bath bomb gas is flammable.

Density of Helium

Watch the video to determine the density of helium.

Density of the Bath Bomb Gas

Watch the video to determine the density of the bath bomb gas.

What we figured out this lesson...

• Density and flammability are properties.

• In high concentrations, gases that are non-flammable will extinguish a flame.

• Gases or liquids that are less dense float upward when surrounded by gases or liquids that are more dense.

• Gases or liquids that are more dense sink downward when surrounded by gases or liquids that are less dense.

• The gas from the bath bomb could be carbon dioxide, nitrogen, or argon.