[christie_uoa]

hi everyone ...
i read in my textbook that halogens cannot exist in elemental state in nature because of their high reactivity. please correct me in the following conclusions i drew if i'm wrong: 1. their high reactivity is due to their electronic structure(ns^2 np^5) 2. therefore we can only find halogens in salts ( or connected to a H+). Am I right or have I missed something?

I'd like to ask something elso too: Last week in the lab we used a reagents which where labeled on their bottles as : Cl2, I2. When we write/say Cl2 or I2 don't we mean that they are in elemental state? Probably not...but then what state are they considered to be in? Also how do we symbolize Chloride or Iodide in their elemental state?

Well...thanks in advance!

[Moonshyne]

A halogen's elemental state is diatomic (excluding astatine). Say like I₂ or Cl₂, this is how the halogen occurs in nature. All diatomic halogens are toxic and also dangerous because they are very strong oxidizing agents. I believe that if a halogen occurs by itself, it can only exist as an ion, such as F^- or Ba^-. In this case it is such a strong reducing agent it basically oxidizes anything it touches, which is why they are so dangerous in this state. So yes their high reactivity is due to their electronic structure (but only since it's a halogen  )

-hope this helps

[christie_uoa]

Well Cotton and Wilkinson in "Advanced Inorganic Chemistry" say exactly that: "Halogens cannot exist in elemental state in Nature..." therefore since halogens are diatomic in elemental state (Cl₂ I₂ etc. ) I can only conclude that halogens cannot occur free in nature in diatomic state but only as salts right?

Basically i'm intrested in finding out the oxidizing state in which halogens are most commonly found in nature...so based on the Frost diagrams it's probably -1 right?

[Mitch]

Don't get to caught up on elemental states. Sulfur exists as S8 in nature and C as huge arrarys of carbon sheets in diamond and charcoal.

[nearly.alex]

a halogen on its own has an unpaired electron there fore it is a free redical and basically reacts with anything and is a very strong reducing agent. in the atomsphere chlorine free radicals are formed and are found as single atoms but react very quickly with the atmosphere (why CFC's make a whole in the ozone).