留言
QB 2017 年 8 月 25 日 上午 12:49 
A pnictogen is one of the chemical elements in group 15 of the periodic table. This group is also known as the nitrogen family. It consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and perhaps also the chemically uncharacterized synthetic element moscovium (Mc).

In modern IUPAC notation, it is called Group 15. In CAS and the old IUPAC systems it was called Group VA and Group VB respectively (pronounced "group five A" and "group five B", "V" for the Roman numeral 5).In the field of semiconductor physics, it is still usually called Group V.The "five" ("V") in the historical names comes from the "pentavalency" of nitrogen, reflected by the stoichiometry of compounds such as N2O5.

The term pnictogen (or pnigogen) is derived from the Ancient Greek word πνίγειν (pnígein) meaning "to choke", referring to the choking or stifling property of nitrogen gas.
QB 2017 年 7 月 9 日 下午 12:28 
Can a match box?
Joschuletz 2017 年 6 月 19 日 上午 11:46 
10/10 testicles guy
QB 2017 年 3 月 3 日 上午 12:16 
Dylanwow
xanny with an z 2017 年 2 月 6 日 下午 9:52 
Deeelannnn
QB 2016 年 11 月 15 日 上午 10:57 
John Carpenter
Ezra Nobleheart 2016 年 2 月 11 日 下午 9:51 
Give This Rose ~ To Everyone You Care About.
_____/)___/)______./¯"""/')
¯¯¯¯¯¯¯¯¯\)¯¯\)¯¯¯'\_„„„,\)

See If You Can Get Or Give A Dozen Before Valentines Day!
dylanhack 2015 年 1 月 9 日 上午 9:27 
@Sukafu, yes, yes you are.
Sukafu 2015 年 1 月 8 日 下午 7:12 
i'm your friend on steam!!!!
dylanhack 2014 年 9 月 28 日 上午 4:41 
@Flamethrower, Hi.
Burnt 2014 年 9 月 27 日 下午 7:11 
hi
dylanhack 2013 年 12 月 17 日 下午 11:22 
@Ari. Hi.
Ari 2013 年 9 月 14 日 下午 7:00 
It won't let me send a message, so Hi!