Is Helium a flammable gas? (A comprehensive overview)

This article will give you the answer to the question “Is Helium a flammable gas?” and it will explain to you what exactly helium gas is. The article will also help you to understand the importance of helium gas, its properties and its uses.

Is Helium a flammable gas?

No, helium is not a flammable gas. Helium is an inert gas. It is an odorless, colorless and tasteless gas. It is a non-toxic and non-reactive gas that belongs to the noble gas category. The symbol, atomic number and atomic mass of helium are given below:

  • Symbol: He
  • Atomic number: 2
  • Atomic mass: 4,00260 g/mol

Discovery of Helium 

Helium was first discovered by Pierre Janssen and Joseph Norman Locker in 1868. Though helium is known to be the second most abundant element in the universe, it is a rare element on earth. Helium was initially found in uranium ores. Hence, we can say that helium can be commonly found in areas where uranium is present.

Helium (as a chemical element)

The atomic number of an element denotes the number of electrons present in it. Helium has two electrons in total. Therefore, the atomic number of helium is 2. This means that helium is the second lightest and second most abundant element in the universe.

Physical Properties of Helium

The physical properties of helium gas are given below:

  • The boiling point of helium is −268.928 °C
  • The melting point of helium is  ​−272.20 °C
  • The density of helium is 0.1786 g/L at standard temperature and pressure (STP)
  • The triple point of helium is 2.177 K, ​5.043 kPa
  • The critical point of helium is 5.1953 K, 0.22746 MPa
  • The heat of vaporization of helium is 0.0829 kJ/mol 
  • The heat of fusion of helium is 0.0138 kJ/mol
  • The molar heat capacity of helium is 20.78 J/(mol·K)

Crystal structure of Helium 

The crystal structure is nothing but the arrangement of atoms, molecules or ions of a system or a crystalline material. It gives you the visualization of how the atoms are arranged in symmetrical patterns that repeat in a three-dimensional space.

The crystal structure of Helium is ​hexagonal close-packed (hcp). This is one of the most common arrangements in elements or materials. HCP, being one of the most stable crystal structures, has the highest packing density. In a hcp arrangement, the unit cell can be imagined as a prism in a hexagonal shape with an atom on each corner and 3 atoms in the centre. This arrangement can be imagined as to be stacked one over the other layer.

Uses of Helium

Helium has a wide range of applications. This is mainly due to its inert and non-reactive nature and also due to its non-flammability.

Some of the uses of helium are as follows:

  • Helium as a coolant
  • Helium in balloons

Helium as a coolant 

Since helium is inert and not a flammable gas, it is even used as a coolant in certain cases. It is used as a coolant in MRI machines, rockets etc. Helium has unique advantages over other gases when used as a coolant, especially in machines that operate above 500°C. This is due to its high thermal conductivity and specific heat capacity.

Helium in balloons

Helium gas is lighter and less dense than air. This is the actual reason why balloons filled with helium gas float. The added property of helium being a non-flammable gas makes it safe for use. Since helium is expensive, hydrogen is being used to inflate gas balloons nowadays. Hydrogen is even lighter than helium and gives the balloon its floatability. However, hydrogen is extremely flammable and not safe for household use. 

Hazards of helium

Although helium is inert and is not a flammable gas, studies show that helium can be dangerous at times. 

Especially when helium is inhaled by humans. Some of the hazards caused by helium are as follows:

  • Skin Hazard
  • Eye Hazard
  • Inhalation Hazard
  • Fire Hazard

Skin Hazard:

Helium is known to cause frostbites when it comes in contact with any liquid. When helium is in its liquid form and it comes in contact with cold water, it can cause severe boiling. This can be avoided by avoiding contact of helium and liquid (cold water) with the skin. Although there is no adverse effect on the skin, it is always better to prevent such situations where helium can come in contact with the skin.

Eye Hazard: 

Helium also causes frostbites and irritation when it comes in contact with the eyes due to the liquid present in the eyes. It is always advisable to avoid contact of helium with the eyes. This can be prevented by washing off the eyes with clean water.  If irritation continues, an ophthalmologist must be contacted immediately. 

Inhalation Hazard:

The most common example of inhaling helium is inhaling it via helium balloons. Although it may appear harmless, inhaling it can pose serious threats to the human body. Some studies show that adolescents exposed to helium inhalation reported that it makes them feel intoxicated and dizzy. Inhalation of Helium can cause tiredness, dizziness and even severe headaches. This is because helium displaces the oxygen in the body as it is less dense than oxygen.

This can be prevented if fresh air is immediately introduced.  Artificial respiration must be given if breathing is difficult. Alternatively, a qualified physician must be called to give external oxygen to the affected person.

Fire Hazard:

Although helium is a non-combustible, inert gas, it can lead to an increase in the pressure of the gas at times, when exposed to fire. This will cause the gas to rupture. 

This can be prevented if an appropriate extinguishing source is used. In case of an accidental release of the gas, people must be evacuated immediately. Wearing self-contained breathing apparatus is advisable in such cases. The leakage must be stopped instantly if the environment is safe enough.

Conclusion

This article addresses the question “Is Helium a flammable gas?” 

The article has given a comprehensive overview of Helium gas and its flammability. The article has also given information about the physical properties, crystal structure, uses and hazards of helium gas.

Please do not hesitate to comment on the above content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): Is Helium a flammable gas?

Does helium catch fire? 

No, helium gas does not catch fire. This means that helium is a non-combustible gas. Due to its inert nature, helium does not cause any chemical reaction when it comes in contact with any other element such as fire. Therefore it does not catch fire because it is a non-reactive and a stable gas.

Can helium gas explode? 

No, helium gas cannot explode. Since helium is not a flammable gas, it does not cause any reaction.

For an explosion to take place, rapid expansion of gases is required. For this, a heat source in the form of a spark, fire or even electricity is a basic requirement.  Since helium is not a flammable gas, it will not explode even in the presence of these basic requirements. For example, a balloon filled with helium gas will cause an explosion.

Is helium a toxic gas? 

No, helium is not a toxic gas.

However, inhalation of helium is not safe for human health. Research says that continuous inhalation of helium, especially when released in high pressure, has also caused death. 

Is helium as flammable as hydrogen? 

No, helium is not as flammable as hydrogen. Hydrogen being the first element of the periodic table, is a highly flammable and reactive gas. It is a much lighter gas than helium. 

What is a noble gas? 

Unlike other gases, noble gases are special gases that are non-reactive and inert. These are special categories of gases that are rare and exhibit great stability and have extremely low reaction rates. They are also called as inert gases.

A few examples of other noble gases are;  neon, argon, krypton, xenon, and radon

Can you burn helium? 

No, you cannot burn helium as it is not flammable and bringing helium gas in contact will not cause any reaction, hence it will not burn.

References

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