It's important to note that although nitrogen is chemically stable and can be used as a protective gas, it is not an inert gas and can react with many substances, and it's not ideal for preserving freshness. In contrast, helium is extremely stable and plays an indispensable role in many industries. So, which is more potent—helium or nitrogen? How should we choose between the two?

Helium has a density of 0.1786 g/L, while nitrogen is at 1.251 g/L, making helium naturally lighter than nitrogen. Thus, helium can be used as a filling gas for aircraft, aside from hydrogen, which is the only other gas capable of floating in the sky. However, if the only consideration is cost, and not the ability to float, both industrial helium and nitrogen can be used to inflate balloons, with nitrogen being more economical. Moreover, helium has the lowest boiling point of all known substances, so while both helium and nitrogen can cool, helium's cooling effect is undoubtedly superior. In reality, liquid helium is an indispensable coolant for many low-temperature physics experiments, while nitrogen cooling is typically used during the rapid evaporation of liquid nitrogen, absorbing a large amount of heat to achieve rapid cooling. However, gaseous nitrogen does not have cooling capabilities.

In terms of ease of acquisition, nitrogen is naturally easier to obtain compared to helium. Everyone is familiar with the methods of producing helium. To obtain helium, one first needs to find natural gas containing helium, then obtain crude helium through various methods, and finally refine it to different purity levels according to demand, which is very costly, driving up the price of helium. In contrast, nitrogen can be obtained simply by distilling liquid air, and it usually appears as a byproduct during the industrial production of oxygen. Moreover, compared to helium, nitrogen has an additional advantage of being obtainable in a laboratory. Helium can be artificially obtained in a lab by methods such as mixing ammonium chloride with sodium nitrite and heating, passing pure air through a hot copper powder or copper mesh to remove oxygen, or by passing ammonia through heated copper oxide. However, there hasn't been any mention of a laboratory method for obtaining helium in Suizhou.