Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: CrzyChnz on 13/10/2013 18:19:57

Title: what is the most reactive element in the world?
Post by: CrzyChnz on 13/10/2013 18:19:57
I am so confused on which element is the most reactive element in the world!!!
Title: Re: what is the most reactive element in the world?
Post by: Kryptid on 14/10/2013 03:47:50
Fluorine. It can burn substances which are generally thought of as nonflammable, such as glass, water and sand. It is the most electronegative of all of the reactive* elements and therefore has an extremely high attraction for electrons. As a consequence, compounds formed from fluorine are often quite stable, such as Teflon and fluorine salts. Lithium and potassium are also extremely reactive, but in a different way since they are electropositive instead of electronegative. Fluorine also reacts more readily than these two elements because it is a gas at standard conditions whereas the alkali metals are solids.

Uranium and plutonium aren't even close.

*Helium and neon have higher electronegativities, but are normally not reactive.
Title: Re: what is the most reactive element in the world?
Post by: CrzyChnz on 14/10/2013 04:50:55
actually after i did a little bit of research, i think francium is a pretty reactive element.
Title: Re: what is the most reactive element in the world?
Post by: CliffordK on 14/10/2013 04:53:06
Don't forget Hydrogen.
It is part of a lot of compounds.  A component of most acids, as well as most bases.  And, of course, also some salts. 
It can apparently be found in both electro positive and electro negative forms.
It generally reduces other elements, but apparently can also act as an oxidizer in some reactions.
Title: Re: what is the most reactive element in the world?
Post by: SorryDnoodle on 17/10/2013 22:47:58
A quick look at a periodic table with electronegativity shows Florine is the most reactive element, atleast when it comes to stealing electrons.
http://0.tqn.com/d/chemistry/1/0/w/v/PeriodicTableElectronegativity.jpg
Title: Re: what is the most reactive element in the world?
Post by: Ophiolite on 18/10/2013 00:22:18
My vote would have been for flourine, but we should recall that it takes two to tango.
Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 19/10/2013 13:05:17
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Title: Re: what is the most reactive element in the world?
Post by: Ophiolite on 19/10/2013 14:33:48
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Would it not be more accurate to say that it is ill-defined and therefore ambiguous? Several interpretations could be placed on the phrase "most reactive". Most, if not all, of these interpretations would represent and meaningful and perhaps interesting question.
Title: Re: what is the most reactive element in the world?
Post by: Bored chemist on 19/10/2013 14:44:37
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Especially when one of the more likely candidates is spelled wrongly.
Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 19/10/2013 18:55:02
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Would it not be more accurate to say that it is ill-defined and therefore ambiguous? Several interpretations could be placed on the phrase "most reactive". Most, if not all, of these interpretations would represent and meaningful and perhaps interesting question.
Yes, but nonetheless the OP question is meningless  [:)]

example 1: which of those elements is most reactive with sodium?
answer   1: fluorine

example 2: which of those elements is most reactive with nitrogen?
answer   2: lithium

example 3: which of those elements is most reactive with chlorine?
answer   3: Certainly not fluorine and not lithium.
Amomg the others, it depends on what you mean with "more reactive": do you mean with lower activation energy? Or with the higher Gibbs energy of reaction? Or do you mean that it ignites more quickly when coming in contact (which depends on the previous two and on other things)? Else?

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lightarrow
Title: Re: what is the most reactive element in the world?
Post by: Ophiolite on 19/10/2013 22:30:26
Thank you for confirming that a number of interesting questions can be asked when more precision is applied to formulating the questions.
Title: Re: what is the most reactive element in the world?
Post by: SorryDnoodle on 19/10/2013 23:47:53
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Especially when one of the more likely candidates is spelled wrongly.

Dyslexia is a female dog, I try not to care anymore if I spell a word wrongly on an internet forum.
Title: Re: what is the most reactive element in the world?
Post by: Bored chemist on 20/10/2013 10:01:15
As many other times answered in this forum, THE QUESTION IS MEANINGLESS.
Especially when one of the more likely candidates is spelled wrongly.

Dyslexia is a female dog, I try not to care anymore if I spell a word wrongly on an internet forum.
I know it is. That's part of the reason why I use Chrome. It highlights errors for me.
Anyway, those people who are saying that the question of "most reactive" is meaningless because it depends on what you are reacting it with have missed the point.
You can look at how each element reacts (or doesn't) with all the other elements.
Then you can see what the "aggregate" reactivity score is.
Fluorine wins.
(Because most elements are metals and the alkali metals don't react much with most other metals.)
Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 20/10/2013 13:02:01
Anyway, those people who are saying that the question of "most reactive" is meaningless because it depends on what you are reacting it with have missed the point.
You can look at how each element reacts (or doesn't) with all the other elements.
Then you can see what the "aggregate" reactivity score is.
Fluorine wins.
(Because most elements are metals and the alkali metals don't react much with most other metals.)
...according to your definition of "most reactive". But, unless I have missed the correct translation from english language (which is possible) this definition is just one of many (or I can find it in a chemistry book?)

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lightarrow
Title: Re: what is the most reactive element in the world?
Post by: Bored chemist on 20/10/2013 14:20:42
I didn't give a definition.
However, unless you can show me the details of the reaction of (for example) potassium with iron or sodium with tantalum my point stands.

A comparable approach would be to look at what elements don't react with a given element.
For example gold only reacts with the halogens (IIRC) Neon doesn't even react with those.
Sodium reacts with most of the non-metals and a few metals (such as mercury)
Fluorine and oxygen react with most of the other elements.
You could quite easily rank all the elements by the number of elements they don't react with.
the one with fewest non-reactions is most reactive.
Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 23/10/2013 22:58:59
I didn't give a definition.
Yes, you did, you have done it even in this very post: <<...the one with fewest non-reactions is most reactive.>>
Title: Re: what is the most reactive element in the world?
Post by: Bored chemist on 24/10/2013 19:39:59
I didn't give a definition.
Yes, you did, you have done it even in this very post: <<...the one with fewest non-reactions is most reactive.>>


Did not is not the same as will not.
However, if you take a definition of the reactivity of an element as being the product of its price and the scrabble score  you can rank them by that.
You can choose from a huge range of definitions if you like and answer the question.
So, in order for the question to have a meaning, there must be a generally accepted definition of chemical reactivity- perhaps a loose one.


You could look at all those possible ranking schemes ( you might want to exclude some silly ones) and then see if there's a consensus of "most reactive".
After all, if you come up with a dozen definitions of "most reactive" and fluorine wins in all of them it's not unreasonable to conclude that it's the most reactive element.







Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 25/10/2013 07:08:14
Did not is not the same as will not.
However, if you take a definition of the reactivity of an element as being the product of its price and the scrabble score  you can rank them by that.
You can choose from a huge range of definitions if you like and answer the question.

So, in order for the question to have a meaning, there must be a generally accepted definition of chemical reactivity- perhaps a loose one.
With fluorine, I think the consensus would be quite universal, but, in general, with a group of elements not containing F?
We *need* a definition.
Title: Re: what is the most reactive element in the world?
Post by: Bored chemist on 25/10/2013 18:21:11
Did not is not the same as will not.
However, if you take a definition of the reactivity of an element as being the product of its price and the scrabble score  you can rank them by that.
You can choose from a huge range of definitions if you like and answer the question.

So, in order for the question to have a meaning, there must be a generally accepted definition of chemical reactivity- perhaps a loose one.
With fluorine, I think the consensus would be quite universal, but, in general, with a group of elements not containing F?
We *need* a definition.
The ones I gave are not copyrighted.
Title: Re: what is the most reactive element in the world?
Post by: lightarrow on 31/10/2013 19:01:18
With fluorine, I think the consensus would be quite universal, but, in general, with a group of elements not containing F?
We *need* a definition.
The ones I gave are not copyrighted.
Ok, but do most of chemists agree on it? If it's so, we could write it in wikipedia.

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lightarrow