Read about Adrian as an Educator of over thirty years, as a Chemistry Tutor with a resume of helping hundreds of private clients over three decades, and as an Author and Writer with an extensive portfolio of work


Read about the the four Core Values that drive all of Adrian’s professional endeavors, and that act as the cornerstones of his work


Check out all of my books


Pretty pictures of my books


Chemistry writing beyond books

The literal application of a pnictogen

Kenneth Eugene Smith - Alabama Dept. of Corrections
January 23, 2024

EDIT 01/26/24: Yesterday, the state of Alabama completed the execution of Kenneth Smith via nitrogen hypoxia.

What do China, Iran, Saudi Arabia, Egypt, the USA and Iraq have in common? They all appear in the Death Penalty Information Center’s (DPIC) top 6 nations* in the world for confirmed executions in 2022.

*Execution totals unknown for North Korea, Vietnam, Syria, and Afghanistan 

A couple of weeks ago I was researching and writing a piece about the Group 15 elements. Plenty of people know the collective names for the elements of groups 1, 2, 17 and 18 (alkali metals, alkaline earth metals, halogens and noble gases), but groups 15 and 16 have slightly more obscure names; the pnictogens and chalcogens respectively.

The word pnictogen comes from the Greek word πνίγω (pnī́gō) meaning “to choke”, and the suffix “-gen” meaning to generate. The origins of the application of the word to the group 15 elements are a little murky, but this 2009 feature from the Journal of Chemical Education summarizes things neatly (and quickly). As author Gregory S. Giorlami notes in the article, the application of the word pnictogen is largely tied to the chemistry of nitrogen which is clearly reflected in the German and French words for element number 7.

“The sense of suffocating is appropriate on chemical grounds, and directly relates to the inability of gaseous nitrogen to support life or combustion, as reflected in the respective German and French names for nitrogen: Stickstoff, or “suffocating substance”, and azote, or “without life”.

Of course, the “suffocating” effects of nitrogen are much more about the lack of oxygen, and breathing in a bunch of N2 isn’t particularly toxic in and of itself, rather the key being the inability of the gas to support respiration (and combustion). The prospect of being forced to breathe pure nitrogen rather than the mixture of oxygen and nitrogen that one normally does in air (approx. 78% N2 and 21% O2) seems beyond terrifying, and would appear to have the potential for a grisly end.

The word ‘appear’ is important here, because the deliberate execution of a person by administering pure nitrogen gas is untested in the USA. Furthermore, according to Robin Maher (Executive Director of the DPIC), there are no known examples of its use worldwide. In that regard, the fact that the state of Alabama is proposing to adopt this method of execution (formally know as nitrogen hypoxia) on Thursday, January 25th 2024 to execute convicted murderer Kenneth Eugene Smith, has many people alarmed.

The use of nitrogen in this manner has been legalized in three states in the USA (Oklahoma, Mississippi and Alabama), and has been driven by the relative unreliability of the lethal injection method, and the reduced availability of the compounds required for it, as many chemical suppliers have pushed back against the use of their products in executions.

Whatever your position on capital punishment, it’s hard for me to believe that if you’re a chemist, the literal application of the word pnictogen wouldn’t at least give you pause.

More links here:



Submit a Comment

Your email address will not be published. Required fields are marked *