Balloon on string would dangling and moving from the wind, it doesn't move on its' own.
The force demonstrated when air rushing out of the neck of a balloon causes the balloon to move is an example of Newton's third law of motion, where for every action there is an equal and opposite reaction. As the air rushes out in one direction, it propels the balloon in the opposite direction.
camarero
One way to put glitter in a balloon without letting the air out is to use a funnel. Insert the funnel into the neck of the balloon and carefully pour the glitter inside. This will prevent air from escaping while filling the balloon with glitter.
If you breath during a chest X-Ray, you can distort the way the X-ray "picture" will be seen. To get an idea of why, imagine holding two balloons filled with air. You are holding the 'neck' without tying off the balloon. With one balloon, hold it so no air escapes ("Hold your breath"). But while holding the one so no air escapes, go ahead and let the air go out a bit from the other. You'll see that balloon "move"... it's outer shell will grow smaller. If you had a high speed camera while letting air out, or blowing up, one balloon, you would see a blurry edge as the one balloon expands or decreases. The same happens with the lungs during breathing as you have an X-Ray; Breathing in and out during the X-Ray will make the image "blurry". ALSO and more importantly, when you are told to "take a deep breath and hold it", you are expanding all the tiny bronchioles inside the lungs. That way, those small tubes get imaged also, so if there is infection or a tiny problem, it will show up in the "picture".
The gases filled within the balloon escape quickly.
what happens when your neck cracks everytime you move it
that is how you get a heart attack or DIE
To blow up a big balloon without a pump, you can simply use your mouth to blow air into the balloon. Hold the neck of the balloon securely while blowing into it to inflate it. It may take a bit more effort and time compared to using a pump, but it is a simple and effective method.
stress
The neck on a bottle.
Stretch the mouth of the deflated water balloon over a tap or other pressurized water source. Turn on the tap so that water rushes into the balloon. Once filled, twist the balloon at the neck a few times. This way water does not escape when you remove the mouth of the balloon from the tap. Once removed, tie the twisted neck of the balloon in a knot to prevent water from escaping.
A tight seal between the balloon and the neck of the bottle is important in order to prevent gas from escaping. This helps to build up pressure inside the bottle, ultimately allowing the balloon to inflate as gas is produced.