Flying balloon cost

The balloon that can fly to the sky is helium balloon, and the inflation cost of helium balloon is close to that of 3 yuan.

Helium is one of the rare gas elements, with the English name helium, the element symbol He, and the atomic number 2. Colorless and odorless inert gas, chemically inactive, is generally difficult to react with other substances.

Helium has stable chemical properties and is dark yellow when discharged at low voltage. Generally, compounds are not generated, but excited in a low-voltage discharge tube, and He2+, HeH plasma and molecules can be formed.