Write the procedure and observation of an experiement to prove that air has mass by using the materials given in the box. Two balloons, scale, cello tape, thread, pin.
Answers
Answer:Science is a way of looking at things, a way of questioning and of figuring out answers by
thinking, by trying them out (experimenting), and by reading about other people’s
experiences and experiments.
A scientist is a person who tries to understand and to find the answers to some of our
questions about the physical world.
You too can be a scientist. To begin, don’t take everything for granted. Start to question
the world around you by performing the experiments in this book. Set aside a special corner
or shelf for your odds and ends of equipment. Ordinary shoeboxes make good storage
bins.
You can perform the experiments safely by following directions and using simple care.
(You can get burnt by drinking an ordinary cup of hot chocolate carelessly!) The
experiments on electricity call for the use of storage batteries or dry cells. It is never
necessary and it is dangerous to use house current. If you are not yet able to cook an egg
over the stove, ask an older friend or adult to help you with those few experiments that
require a candle or other source of heat. Always keep a basin of cold water handy.
If an experiment fails to work, try it again—and find out why it failed the first time.
Sometimes you can learn more from failure than from success.
While you may start with an experiment from any chapter, it is best to concentrate on one
chapter at a time and perform, most of the experiments, preferably in the order given, before
you go on to another topic. The experiments are not meant to be tricks with which to amaze
yourself and your friends (though they may do that, tool), but to provide experiences and to
illustrate scientific principles. The world of fact, you will find, can be more exciting than the
world of fancy.
DOES AIR TAKE UP SPACE?
1. MATTER: AIR
CAN YOU FILL THE EMPTY BOTTLE?
Stuff a large handkerchief or some crumpled
newspaper into an empty glass or jar. Make sure
the handkerchief won’t fall out when you turn the
glass upside down.
Then, fill a pot with water. Holding the glass so
that its mouth is down, put the glass deep into the
pot of water and hold it there. After a minute or
two, pull the glass out of the water and remove the
handkerchief.
You will see that: The handkerchief is dry.
Explanation: Water cannot fill the glass because
the glass is already ~lled with air. The “empty”
glass is full of air. So, air takes up space.
Air is a gas. It has no size or shape of its own but
will fill every space it can.
Place a funnel in the neck of an empty soda bottle.
Pack clay around the neck of the bottle so that there is
no space between the bottle and the funnel.
Pour water into the funnel. Notice what happens.
Then take the clay off the bottle and funnel.
You will see that: While the clay is there, the water
remains in the funnel or enters the bottle only in slow
spurts. When the clay is removed, the water flows
freely into the bottle.
Explanation: The clay seals the neck of the bottle
outside of the funnel. When water flows into the
funnel, the air cannot escape except by going through
the water very slowly. The air in the bottle takes up
space and prevents the water from coming in. When
the clay is removed and air is able to leave around the
neck of the bottle, then water can flow in. This proves
that air takes up space.
DOES AIR WEIGH ANYTHING?
WHICH IS HEAVIER, HOT AIR OR COLD?
Drill holes (or make notches) 6 inches from each end of a narrow 3-foot length of
wood, such as a yardstick. Then, make a hole in the exact center of the stick, 18 inches
from each end. Place a cord or wire through the center hole and suspend the stick
from a chair back or a rod.
Blow up a large balloon or beach ball. Tie its mouth tight and hang it from one of the
end holes of the stick. Then, suspend a small can or box (such as a baking powder
container ) from the other hole. (See illustration.) Put a little sand or rice in the can until
the stick balances.
Then, let the air out of the balloon.
You will see that: The can sinks down as the air is let out of the balloon.
Explanation: When the air leaves the balloon, the balloon becomes lighter. Air has
weight.
At sea level, air weighs 1.25 ounces per cubic foot. (See if you can find a carton, or
stack up books, to measure 1 foot wide, 1 foot long and 1 foot deep. Then you will
know the space taken up by 1~ ounces of air. ) On a mountaintop, air is a little thinner
and weighs less.
Balance an “empty” baby bottle on one
end of your yardstick and a tin can on the
other. Put sand or rice in the can if needed.
Hold a candle flame for one minute near
the mouth of the bottle. Remove the flame
and balance the scale again.
You will see that: The bottle goes up when
heat is applied to the air in it. You must
remove sand or rice from the can on the
other end to balance the scale.
Explanation: Warm air weighs less than
cold air occupying the same space.
Explanation: