Holmium can absorb neutrons, so it is used in nuclear reactors to keep a chain reaction under control. Its alloys are used in some magnets. Holmium has no known biological role, and is non-toxic. Holmium is found as a minor component of the minerals monazite and bastnaesite.
Answer: It is the first one. First: 3 upper C u right arrow 3 Upper C u superscript 2 plus, plus 6 e superscript minus. Second: 2 upper N superscript 5 plus, plus 6 e superscript minus right arrow 2 upper N superscript 2 plus.
