water vapor.
Because it has air in it. Air weighs less than water therefore air floats.
air, a cookie crumb or a fruit fly
An airship uses helium which weighs less than air, and it cancels out the weight of the airship. Hydrogen weighs even less than helium, but it is combustible, so helium is preferred for use in airships.
water is more dense than air and it has at
Yes, an empty balloon weighs less than a balloon filled with air because the air adds to the overall weight of the balloon.
An inflated balloon weighs more than a deflated one because the air inside adds mass to the balloon. When the balloon is deflated, it contains less air or no air at all, resulting in less weight.
An innertube floats for the same reason that a balloon filled with helium floats in the air. In a helium balloon the gas is lighter than the air. Air in an innertube weighs less than the water and therefore floats to the top. This is called buoyancy. It weighs less than the water but more than the air above the water due to the rubber of the tube. This is why it stays on the surface and does not float away into the sky.
The balloon fish will float because it weighs less than the volume of water it displaces. By swallowing air, the fish increases its volume without significantly increasing its weight, allowing it to float at the water's surface.
warm air is less dense than cold air due to the fact that the molecules in warm air have more energy and thus move farther apart from each other. This results in less mass per unit volume of warm air compared to cold air.
Air, of course.
A balloon filled with helium flies because helium weighs less than air.
The bottle of helium gas would weigh less than the identical bottle filled with air at the same pressure. Helium is less dense than air, so a bottle filled with helium weighs less due to the difference in density of the two gases.