Reef Chemistry Question of the Day #76 Halides

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #76

Halides are a family of ions that are very important, both in seawater and in metal halide lamps. Which of the following is not a halide?


A. Fluoride
B. Chloride
C. Bromide
D. Iodide
E. Actinide

Good luck!




















.

 

[Rybren]

E. Actinide

 

[Zero Nitrates]

Going with b

 

[phillrodrigo]

Going with E

 

[Randy Holmes-Farley]

And the answer is...E. Actinide
Good job guys.

Looking at a periodic table (link below) we see all of the halogens in the second to the far right column.
In order from the top (with the name of the negatively charged ion in parentheses), they are fluorine (fluoride), chlorine (chloride), bromine (bromide), iodine (iodide) and astatine (an unstable radiochemical).

Actinide sounds similar, but is very different. It is a name that refers to all of the very heavy elements listed across the bottom of the table, including uranium and plutonium.


http://www.bpc.edu/mathscience/chemistry/images/periodic_table_of_elements.jpg

Happy Reefing!