Why do balloons filled with helium rise to the air?

Answer 1

Hydrogen gas is the lightest of gases. A balloon filled with it certainly WILL rise,

unless the balloon is in a vacuum or a hydrogen atmosphere, or has a heavy

weight hanging from it. The first large "airships" ... zeppelins and blimps ... were

filled with hydrogen.

Answer 2

Simple answer: It can float.

ANS#2 An object will float if the upward force on it is greater than the downward force on it. The volume of the fluid or gas that an object displaces produces the upward force as it is pulled downward by gravity. Gravity, operating on denser fluids and gases produces a greater downward force per unit volume for substances that are denser than it does on less dense objects of the same volume. Hydrogen gas (H2) has a molecular weight of (1.00794 g/mol x 2 = ) 2.01588 g/mol. Air is composed of (mostly) 79% Nitrogen, and 19.8% Oxygen. To simplify, let's ignore the other gases such as carbon dioxide, argon and the rest--none of which make up more than 1% by themselves and say that air is 80% Nitrogen and 20% Oxygen. Oxygen has a molecular weight of (15.994 g/mol x 2 = ) 31.99 g/mol Nitrogen has a molecular weight of 14.00674 g/mol x 2 = ) 28.01 g/mol 1 mole of hydrogen gas at standard temperature and pressure occupies a volume of 22.4 Liters and has the mass of 2.01588 grams. The density of hydrogen gas at STP is 2.01588 g per 22.4 L = 0.09 g/L 1 mole of air molecules at standard temperature and pressure occupies a volume of 22.4 Liters and since it is 80% Nitrogen and 20% oxygen, the combined mass will be (28.01 g x 0.80) + (31.99 g x 0.20) = 22.408 g + 6.398 g = 28.806 g The density of air at STP is 28.806 grams per 22.4 L = 1.29 g/L Since a balloon has negligible internal pressure and, usually is considered to be without mass and dimensionless in this sort of a question, we are left to compare the densities of the gases. The volume of the gas in the balloon is the same as the air that the balloon displaces so we can ignore the volume and look only at the masses of the gases. Each 0.09 gram of hydrogen is displacing 1.29 grams of air. Since gravity pulls both gases, the denser air will displace the less dense hydrogen upwards and the balloon will float. Several reasons: * There is a weight tied to the balloon, * The room is filled with hydrogen (or some other very light gas) instead of air, * The balloon is a real balloon (not a perfect textbook balloon) without enough hydrogen volume to lift the weight of the balloon, * The balloon you observed is not actually filled with hydrogen, * The balloon is actually filled with a hydrogen compound (like water), * You are observing the balloon operating in a weightless environment such as on an orbiting space station, * You observed the wrong balloon.

Answer 3

Hydrogen is lighter than air, so any balloon filled with H2 gas will float. The problem is that hydrogen gas reacts extremely well with oxygen, meaning that its VERY flammable.

The original airships of the 19th century and early twentieth used to be filled with hydrogen gas, and were known as Zeppelins. This mode of flight by airship was generally abandoned after the disaster of the zeppelin Hindenburg in Trenton New Jersey in 1919, when the hydrogen gas filling the airship exploded during an electric storm.

Answer 4

For exactly the same reason that some objects float in water.

An object surrounded by a fluid is buoyed up by a force that's equal to the

weight of the displaced amount of fluid. Doesn't matter whether the fluid is

water, air, oil, or jello before it sets.

Answer 5

Objects float when they are lighter than the medium that they are in. So, a balloon filled with air will float on the water. It doesn't float in the air because air in a balloon isn't lighter than the air outside the balloon (and the balloon itself is made of rubber which is denser than air).

Answer 6

The same reason that makes ships float.

The weight of the helium-filled balloon is less than the weight of the air the balloon displaces(=pushes aside), so it'll rise. Unless it pops or leaks, it'll continue to rise until the air around it is so thin that'it'll weigh the same as the balloon. That'll be the "surface" where the balloon will "float" just like a boat.

It is lighter than air itself.

The mass of 1.0 mole Helium gas (22,4 L at STP) has mass of 4 grams.

The mass of 1.0 mole air (mainly 80% N2 and 20% O2) is 28.8 gram, so 7 times heavier for 22,4 L at STP.
Because helium is lighter than air.
the density of helium is less than the density of air
The air in the atmosphere is denser than helium, so helium floats. Thus when helium is pumped into the balloons, it carries the balloon upand helium is also used for many things like welding etc.....

Answer 7

a hydrogen atom is very light. most of the air on earth is made up of nitrogen, oxygen, and carbon dioxide. all of these elements are heavier than hydrogen, so the balloon is pushed upwards. think of oil and water.

Answer 8

Because Hydrogen is very light in density compared to air.

Answer 9

A hydrogen balloon will rise into the air, but it will deflate very quickly.