Rust Uses up Oxygen
You will need: Steel wool, pencil, rubber band, water glass, dish of water.
Burning and breathing are not the only means of using oxygen from the air. Whenever iron rusts, oxygen is used up in the process.
We can prove this by a simple experiment, but one which is going to need some time. Moisten some steel wool in water and secure it to the top of a pencil with a rubber band, as shown in Fig. 1. Fill a dish with water and arrange the pencil and steel wool inside an upturned glass (Fig. 2).
Place the dish and its contents in a safe place
and leave it for several days. After a sufficient lapse of time you will find
that the steel wool has begun to rust. In doing so it will have used up oxygen
from the air in the glass. Also the outer air will have forced up the level of
the water inside the glass to offset the area of low pressure caused by the
rusting of the metal. When all the oxygen has been used, the water will have
risen to about one-fifth of the volume of the water glass.
Children learn best through doing
Before children can understand a thing, they need experience: seeing, touching, hearing, tasting, smelling; choosing, arranging, putting things together, taking things apart. Experimenting with real things.
Old-time school teaching used only words and the teachers thought children knew something if they could repeat it. Now we know better. To reach practical understanding we do not need to use many words with young children.
Children are clever. They learn a lot, without being taught. The greatest skill - to be able to talk, to communicate is learnt outside school. In the classroom it's the children who need to talk the most. Unfortunately it is the teacher who does most of the talking!
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