Nitrogen (N) in its atmospheric form (N₂) makes up approximately 78 percent of the air we breathe. When bacteria living within plant roots convert it into a usable form through a process called nitrogen fixation, this elemental form of nitrogen gets incorporated into many compounds that are necessary for life—proteins and DNA, for example. At the bottom of the column is Moscovium (Mc), which is interesting because it doesn't really exist in nature. It's a radioactive element that can only be generated in a laboratory and survives for less than a second.
Arsenic (As) may be familiar to you because of its association with poisonings. In 1494, Pico della Mirandola, an Italian humanist philosopher during the Renaissance, was poisoned by arsenic, although the details surrounding his early death are still debated. For a long time it was believed that Napoleon Bonaparte died of arsenic exposure in 1821, but after extensive comparisons of preserved hair samples from different stages of his life, researchers concluded the increased levels of arsenic were most likely due to preservation techniques of the time. More recently, the World Health Organization estimated arsenic-contaminated drinking water in Bangladesh resulted in over 9,000 deaths in 2001. How arsenic poisons and kills isn't completely understood.