The Periodic Table of Endangered Elements

American Chemical Society rerports (LINK) that: "Of the 118 elements that make up everything—from the compounds in a chemists arsenal to consumer products on the shelf—44 will face supply limitations in the coming years. These critical elements include rare earth elements, precious metals, and even life essentials like Phosphorus. Research into more abundant alternatives, more efficient uses, recycling and recovery will help mitigate risks and move industry towards sustainable supply chains."

The Period Table of Endangered Elements presents elements facing supply restrictions in the coming years. The research was conducted by the Chemical Innovation Knowledge Transfer Network.

According to the sudy by the Chemical Innovation Knowledge Transfer Network the availability of the following elements are listed as having a serious threat: Hafnium (Hf), Silver (Ag), Zinc (Zn), Gallium (Ga), Indium (In), Germanium (Ge), Arsenic (As), Tellurium (Te) and Helium (He).

A sample of a 1,7kg Hafnium crystal bar, made by van Arkel-de Boer process. [Wikipedia]

Just to grasp the situation - all of these ellemnts are used in high volume manufacturing in the electronics and semiconductor industry today. If you only look at hafnium, you will notice that it is used in many high-tech industries today in high-temperature turbines, aersospace applications including rocket engine nozzles and ceramics for thermal shielding, plasma cutting inserts and welding torches, plastics manufacturing, in commercial control rod assemblies for nuclear reactors, as high-k gate insulators and dielectrics in logic and memory microchips. [Alkane Resources]

As reported by USGS - China and Morocco are the leading global producers of arsenic trioxide, accounting for 87% of estimated world production. China is the leading world producer of arsenic metal and as an example supplied about 89% of U.S. arsenic metal imports in 2016. [LINK]

As for Arsenic, most people may first think of it as a poisonand in that case actually arsenic tri oxide (As2O3) of which approximately 50,000 tonnes are produced annually with application ranging from medical to wood impregnation. The primary use of metallic arsenic is in alloys of lead (for example, in car batteries and ammunition). More recently, Gallium arsenide has become an important semiconductor material, used in integrated circuits. Circuits made from GaAs are much faster (but also much more expensive) than those made from silicon. Unlike silicon, GaAs has a direct bandgap, and can be used in laser diodes and LEDs to convert electrical energy directly into light. [Wikipedia]

On the other hand a gas like helium is well known for use in balloons however, they are a minor part of all helium use. Other applications include : protective gas for welding, vacuum leak detection, neutral heat conductive gas in heating and cooling reactive ion etching, protective gas in growing silicon and germanium crystals, in titanium and zirconium production, and in gas chromatography, supersonic wind tunnels and impulse facilities. Importantly, helium at low temperatures is used in cryogenics, and in certain cryogenics applications. As examples of applications, liquid helium is used to cool certain metals to the extremely low temperatures required for superconductivity, such as in superconducting magnets for magnetic resonance imaging. The Large Hadron Collider at CERN uses 96 metric tons of liquid helium to maintain the temperature at 1.9 kelvin. [Wikipedia] 

A section of the LHC, the Large Hadron Collider at CERN uses 96 metric tons of liquid helium to maintain the temperature at 1.9 kelvin [Wikipedia]