Ghost Fog/ Cloud in a Jar- discrepant event
Materials Required
What To Do :
Clear glass or plastic jar, preferably large
Warm water (about ½ cup, warm tap water will do)
Matches
Bag of ice
Flashlight (optional)
Black paper (optional)
Pour enough warm water into the jar to just cover the bottom of the jar. Stick the bag of ice on top of the
mouth of the jar so that the mouth is completely covered.
Observe that the air inside the jar stays clear.
Now, remove the bag of ice and light a match, holding it just inside the mouth of the jar.
Blow it out, letting some smoke go into the jar.
Replace the bag of ice, and wait about 30 seconds.
This is a good time to ask the students to predict what might happen.
As everyone waits, a cloud of fog will form inside the jar.
Use the flashlight to illuminate the fog, or use the black paper as a background to make it more visible.
Do not read the background information until after completing the discrepant event.
How Clouds Form
A cloud is composed of tiny water droplets or ice crystals that are suspended in the air. A series of processes have to happen in order for these water
droplets or ice crystals to form into clouds in the atmosphere, and different types of clouds
(http://www.windows2universe.org/earth/Atmosphere/clouds/cloud_types.html) form from different processes. The four main ways that clouds can form are:
 Surface Heating,
 Air Masses Being Forced to Rise
 Mountains and Terrain
 Weather Fronts (cold or warm)
All of these processes involve the cooling of air. In general, first the air must be moist – saturated with moisture. Warm air is able to hold larger amounts
of water vapor than cool air, so when air cools it is no longer able to hold all of the water vapour it was able to hold when it was warm. This extra water
vapour begins to condense out of the air into liquid water droplets.
Typically, water vapour needs some sort of particle, such as smoke,
microscopic dust, pollen or salt particles to condense upon. They are the
“seeds” that are required for clouds to form in the atmosphere. These particles
are called condensation nuclei. Eventually, enough water vapour will
condense upon condensation nuclei to form a cloud. The water droplets in the
cloud may eventually fall down to Earth in the form of rain or snow (or other
forms of precipitation). Thus clouds often form when a warm, moist air mass
encounters a cold air mass, and there are condensation nuclei present.
This experiment is a good way to begin a review of the hydrosphere and
atmosphere, as clouds are formed in the atmosphere and are part of the water
cycle. Also, using the flashlight can demonstrate how clouds interfere with
absorption of solar radiation and how they have their own albedo. Finally, the
fact that humans play a part in the amount of dust and pollution in the
atmosphere can be explored by realizing that we have an impact on cloud
formation, leading to severe weather.
Nature of SCIENCE FOCUS bites 2014
Understanding about
Science
Learn about science as a knowledge system: the
features of scientific knowledge and the
processes by which it is developed; and learn
about the ways in which the work of scientists
interacts with society.
Achievement
Objectives level 1 & 2
Using evidence
Science is a way of explaining the world. Science is empirical
and measurable. This means that in science, explanations need
to be supported by evidence that is based on, or derived from,
observations of the natural world
At the very core of science is theory building – making better
explanations. What sets scientific explanations apart from other
ways of explaining the world is their reliance on evidence and
their ability to evolve as new evidence comes to light
Scientifically literate citizens understand the importance of a
sceptical disposition towards all empirical evidence and the role of
argument (in science) and critique in the construction of knowledge
in science.
Achievement
Objectives level 3 & 4
New language…
• Appreciate that scientists ask
questions about our world that lead to
investigations and that openmindedness is important because there
may be more than one explanation.
• Appreciate that science is a way of
explaining the world and that science
knowledge changes over time.
• Identify ways in which scientists
work together and provide evidence to
support their ideas
How do you know that? ; there is
water vapour inside the glass?
What makes you think so?
Making careful observations to use
as evidence, what do you see in the
jar at first? What changes?
Does the evidence change your
ideas/ thinking? ; about what clouds
are and how they are formed? About
how human activities could affect the
clouds and the weather. ;
Investigating in Science
Communicating in
Science
Participating and
contributing
Develop knowledge of the vocabulary,
numeric and symbol systems, and
conventions of science and use this
knowledge to communicate about their
own and others’ ideas
Bring a scientific perspective to
decisions and actions as appropriate.
• Extend their experiences and personal
explanations of the natural world through
exploration, play, asking questions, and
discussing simple models.
• Build their language and
develop their understandings of
the many ways the natural world
can be represented.
• Explore and act on issues
and questions that link their
science learning to their daily
living.
• Build on prior experiences, working
together to share and examine their own
and others’ knowledge.
• Ask questions, find evidence, explore
simple models, and carry out appropriate
investigations to develop simple
explanations.
How could you check that? There is
water vapour in the fog? That there is
water vapour in the air?
So an example of this would be...
Can you think of an example when
this wouldn’t work?
Gathering evidence to test their
science idea, what does it look like?
Smell like? Feel like?
Developing explanations based on
evidence
Using evidence to support their ideas.
Why doesn’t fog form with just warm,
moist air meeting cool air?
Is there enough evidence to support
your ideas?
Why does the fog come out in wisps
when the bag of ice is removed from the
mouth of the jar?
• Begin to use a range of scientific
symbols, conventions, and
vocabulary.
• Engage with a range of science
texts and begin to question the
purposes for which these texts are
constructed.
Sharing explanations of
experiences and observations
from the evidence
• Use their growing science
knowledge when considering
issues of concern to them
• Explore various aspects of an
issue and make decisions
about possible actions
Carry out science investigations using a variety of
approaches: classifying and identifying, pattern
seeking, exploring, investigating models, fair testing,
making things, or developing systems
My observations / visual/ written…
Give opportunities for
practicing evidence-based
talk: e.g. I think… because…
What if we used something
other than smoke? What could
we use?
Make a summary of what you
noticed
Use a table to record evidence
to draw on your own
investigation.
Making decisions based on
evidence- How will this
knowledge help you in your
daily life? how the weather
would change without
human influence?
Justify an opinion based
on their scientific
knowledge using evidence
Do you need to consider
multiple pieces of evidence
before making a judgment?
Why the match is required
to form the fog?