I would highly suggest “splitting” your screen to make it easier for you to work with the
simulation and answer the questions at the same time. Please also leave the pre-set blue
font color when typing out your answers.
Prior Knowledge Question (Do this BEFORE using the Gizmo.)
A small helium tank measures about two feet (60 cm) high. Yet it can fill over 50 balloons! How can such a
small tank contain enough helium to fill so many balloons?
Only a few molecules of helium are needed to fill a balloon because there are so many molecules in one
tank.
Gizmo Warm-up
This Gizmo shows a container of gas. Inside, small purple spheres represent gas molecules.
bserve the particles for one minute. Are they all moving at the same speed?
1. O
No, the particles are moving at different speeds.
2. H
ow do the particles interact with the walls and lid of the container?
The particles bounce off of the lid and the walls of the container.
These interactions contribute to the pressure on the walls of the container. Pressure is defined as force per
unit area. The SI units of pressure are newtons per square meter (N/m2), or pascals (Pa).
3. Slowly drag the temperature (T) slider back and forth. (Note: In this Gizmo, the Kelvin scale is used to
measure temperature. On the Kelvin scale, 0 degrees is absolute zero, the coldest possible temperature.
Absolute zero is equal to -273.15 °C or -459.67 °F)
A. H
ow does the change in temperature affect the speed of the molecules?
The higher the Kelvin temperature is, the faster the particles move. However, if the kelvin temperature is
lower, the particles move slower.
B. H
ow does the change in temperature affect the volume of the container?
The higher the temperature is, the more volume there is. The lower the temperature is, the less volume
there is of the container.
Get the Gizmo ready:
· Set the temperature (T) to 300 K.
· Check that the mass (m) is set to 0 kg.
Question: How does pressure affect the volume of a gas?