Generally, it is helium. Hydrogen could work, but that would be dangerous.
To rise, they need something to float on - i.e., air.
Hot air rises cold air falls, a example of this is hot-air balloons, hot-air balloons use a fire to heat up the air inside it so it will rise and they also have a latch to relase some of the hot air so that the ballon will desend.
Hot air is used for hot air balloons.
Helium
The shape and the size of a toy balloons doesn't depend on the kind of gas inside.
they have a fetish
Helium is lighter than air, hence balloons filled with helium will float and rise up.
No, balloons are not magnetic. If they rise, that has nothing to do with magnetism.
Balloons that are filled with hot air, hydrogen, or helium will float, or rise upward, because the less-dense gases inside them are displaced by the heavier air around them. Balloons will only rise until the gas density inside them is equal to the density outside. In the case of helium balloons, this may be above the elastic limit of the balloon, and it will pop or leak.
i dont really know
At a hot air balloon festival, hot air balloons slowly fill and then rise majestically in the predawn sky. These hot air balloons fly because of two fundamental principles of physics: the ideal gas law and Archimedes's principle.
yes honey, that's why hot air balloons rise
This gas is helium.
'Helium' because it is also an INERT (Noble) gas. Hydrogen could be used to make the balloon float/rise, but hydrogen is a flammable gas. On explosion you will have a flash of flame.
hang from the ceiling
Down from ceiling
there are many different types: hot air balloons, gas balloons, party balloons, weather balloons and many more complex types of balloons.