A hot air balloon doesn't contain helium or hydrogen.
Anything less dense than air (hydrogen, helium, hot air).
'Hot air' balloons don't use hydrogen. They use hot air. Balloons that use hydrogen are not referred to as 'hot air' balloons. The only balloons that can accurately be referred to as 'hot air' balloons are the members of the balloon population that derive their lift/buoyancy from the presence of hot air. Of course, if a balloon used no hot air, then it could freely be referred to as a 'hydrogen' balloon, a 'helium' balloon, a 'water' balloon, etc., depending in congruent harmony with the nature of whatever substance had been chosen with which to inflate it it in order to maintain its fulsome shape.
I'm fairly certain that both hydrogen and helium are lighter then air. Example, if you filled a balloon with either the balloon would float. And both are combustible. Hydrogen is some what more dramatic in its combustion however, the tragic example being the hindenburg.
A helium balloon rises into the air because the density of the helium is lesser than the density of the air, therefore, the balloon rises, trying to reach above the air. Helium is lighter than air, or to be more precise, less dense. Helium gas weighs less than our atmospheric air so it floats. Same goes for hydrogen and a few other pure gases
Balloons are filled with gas (such as helium), or a mixture of gasses (such as air) or hot gasses (such as hot air).Helium.
There are actually a number of ways to make a balloon lift, without helium. Hydrogen is even less dense than helium (but has the disadvantage of also being highly flammable). And since hot air is less dense than cooler air, you can lift a balloon just by heating air. Since hot air is less expensive than either helium or hydrogen, that is a popular technique.
Inside a balloon there is gas. This gas is normally helium if you want the balloon to fly high, but hydrogen also works.
Yes, the buoyant force on the balloon will increase when less dense hydrogen is used instead of helium. This is because hydrogen is even less dense than helium, so the overall density of the balloon-hydrogen system decreases, leading to a greater displacement of air and therefore a stronger upward buoyant force.
Contemporary weather balloons are usually filled with helium. Helium is lighter than air, and this allows the balloon to rise as this gas is lighter than air.Hydrogen would also work as it has a low density, like helium. And hydrogen is a bit cheaper than helium because it can be "made" from water. But hydrogen is flammable or even explosive, and it is generally not used for that reason.
A balloon filled with normal air is heavier because the air inside has more mass compared to helium. The density of normal air is higher than helium, so the balloon filled with normal air will weigh more.
I would say an air filled balloon if you fill it with just plain air. I am basing this on the principle of osmosis and diffusion. A substance such as a gas will travel from an area of increased concentration, such as a balloon filled with helium, to an area od decreased concentration, such as the room the balloon is in. If you fill the balloon with air identicle to that in the surrounding room it negates diffusion.
There are actually a number of ways to make a balloon lift, without helium. Hydrogen is even less dense than helium (but has the disadvantage of also being highly flammable). And since hot air is less dense than cooler air, you can lift a balloon just by heating air. Since hot air is less expensive than either helium or hydrogen, that is a popular technique.