Young scientistsPart 1 – Air

Video Conference - Austria

Preparations for the video conference Nov. 12th 2014

Since it is very difficult to explain, particularly young children, air and

air pollution, it is necessary to discuss some things in advance.

Only one candle in 40 seconds

Smog

Experiment 1: You need

• A big glass

• Matches

• A piece of paper

• A piece of aluminium foil

• Ice-bag

What to do:

• Explain that the class will perform and experiment in which they will create artificial "smog" in a jar. Make sure that students understand that the jar is only a model, and models by nature are limited. For example, the purpose of this model is to illustrate the appearance and behavior of smog, not the composition or effects. It is important to understand that smog is not just a "smoky fog", but a specific phenomenon.

• Select students to perform the experiment. Have them cut a strip of paper about 6 inches by 2 inches. Fold the strip in half and twist it into a rope.

• Have them make a snug lid for the jar out of a piece of aluminum foil. Shape a small depression in the foil lid to keep the ice cubes from sliding off. Carefully remove the foil and set it aside.

• Have the students put some water in the jar and swish it around to wet all the inside of the jar. Pour out the extra water.

• Have them light the paper "rope" with a match and drop it and the match into the damp jar. Put the foil lid back on the jar and seal it tightly. Put ice cubes on the lid to make it cold. (The ice cubes will make the water vapor in the jar condense.) You must do this step very quickly, perhaps with some assistance.

Background (for elder pupils)• The expression "smog" was first used in "Turn-of-the-Century" London to describe a

combination of "smoke" and "fog". Smog occurred when water vapor in the air condensed on small particles of soot in the air, forming small smog droplets. Thousands of Londoners died of pneumonia-like diseases due to the poisonous air.

• Today, smog is usually produced photochemically, when chemical pollutants in the air (notably nitrogen oxides and volatile organic compounds (VOC's) from automobile exhausts) are baked by the sun and react chemically. Ground-level ozone is produced by a combination of pollutants from many sources such as automobile exhausts, smokestacks, and fumes (VOC's) from chemical solvents like paint thinner or pesticides. When these smog-forming pollutants (called "precursors") are released into the air, they undergo chemical transformations and produce smog. Weather conditions, such as the lack of wind or a "thermal inversion", also cause smog to be trapped over a particular area.

• Smog causes health problems such as difficulty in breathing, asthma, reduced resistance to lung infections, colds, and eye irritation. The ozone in smog also can damage plants and trees, and the haze reduces visibility. This is particularly noticeable from mountains and other beautiful vistas such as National Parks.

• Severe smog and ground-level ozone problems exist in many major cities, including much of California from San Francisco to San Diego, the mid-Atlantic seaboard from Washington, DC to southern Maine, and over most major cities of the South and Midwest.

Experiment 2: You need

• 2 jam glasses• 2 pieces of

paper• 2 matches• Ice-bag• Hot iron

Inversion weather conditions prevent a normal air exchange. Here there are cold air masses near the bottom of superimposed of warmer air layers. The normal temperature pattern: warm down - so colder above is reversed (Latin inversus.). Normally, the sun heats the ground, the air is heated and rises to the top. The waste gases and smoke are transported into the upper layers of air and severely diluted. Not so with inversion. The normal vertical exchange of air is prevented. Therefore, more exhaust gases accumulate near the ground .

What to do:

There also exists the “Los Angeles” smog. It occurs in the summer in very hot days when a total of too many cars exhaust gases are emitted and in addition much ozone is formed. Pollutants such as soot, SO2, NOx, inter alia, although nowadays these are already well filter out or they do not arise.

• Turn the iron on hot (cotton).• Give little loosely crumpled

paper both glasses• If the iron is hot, set fire to the

paper.• Holding the hot iron about 1 -

1½ inches above the jar with the burning paper.

• The procedure with the second glass - only covered not hot but cold.

• Compare and explain the phenomenon Smog inversion weather conditions.

Experiment 3: You need:

• A glass

• Lime water

• A straw

• disposable syringe

Inhaled and exhaled air differ.The air that surrounds us consistis of many components. The air we breathe must contain enough oxygen because our body uses oxygen. When the body consumes oxygen, then should the air we breathe be different from the air we exhale. We want to test this today. It is a test for the detection of carbon dioxide through lime water.

What to do

• The lime water in the glass is a colorless and odorless liquid.• The syringe is mounted with ambient air (eg. the one we breathe).• The air in the syringe is pressed into the glass with lime water. The color of the lime water does not change.• Air Now is inhaled and exhaled through the straw in the glass with lime water: The limewater becomes cloudy as lime (calcium carbonate CaCO3 =) as sparingly soluble salt.• The turbidity thus proves carbon dioxide in exhaled air.• As in the first part (syringe with ambient air) no change in the lime water (no turbidity) occurs, inhaled and exhaled air may be qualitatively different from each other.

Be careful!

• The lime water has a corrosive effect! For small children there is a risk that they do not exhale through the straw, but soak the lime water!• It is essential to ensure that the syringe is clean and dry, otherwise in the first part of the experiment, a haze of lime water would occur due to dirt or traces of tap water, which is not desirable at this point.

The last thing to do:

• May be our pupils can find out in groups what WE can do to avoid air pollution.

• Our pupils are the future, they have to make it better!

• May be they can create posters!

• Please post some pictures of those posters on Twin space!

See you on Wednesday, November 12th 2014, 11:00 a.m.