Talk:Reactivity series

Potassium should be above Sodium

in the simplified reactivity series, sodium should be below potassium as potassium have one more shell than sodium which is far from the nucleus and is readily able to be lost.

Hellclanner (talk) 01:52, 18 October 2008 (UTC)[reply]

I'm not a metals chemist, but I am an engineer and chemistry teacher. Looking to the CRC standard reduction potentials, the ordering is Li -3.405V, K -2.924V, Na - 2.7109V. Why isn't this consistent with the listed reaction series? I am well aware of general periodic trends which is what you are quoting. But isn't reactivity in a replacement reaction, which is an oxidation-reduction reaction, governed by reduction potential? This is what I was generally taught to go by, not a list of reactivity series...although the list that I have in a couple of handy texts agrees with the reduction potential ordering.

Previous respondents: I am a professional metals chemist. This series is indeed correct. If you read the article carefully, you will find the explanation. This series, and perhaps your confusion relating to the UK-US difference, is a RE-activity series, where most likely an American text book will show you an Activity series. K is indeed more reactive than Na, which is indeed more reactive than Li. This can be proven with a simple experiment in which you drop a small piece of each metal into separate beakers of water. The reason, as described below, is that reactivity increases as you go down a group on the Periodic Table. Li finds its valence (outer shell, reacting) electrons in the second shell, relatively close to the nucleus, from which the protons exhert a hold on the electrons. Na finds its valence electrons is the third shell, slightly farther away from the nucleus and therefore the protons exhibit less attractive force on the valence electrons. Consequently, Na loses that valence electron just a little bit easier that Li does. And so on, all the way down to Francium. Before you post to a public forum, please educate yourself to the facts. As one respondent notes below, s/he is no chemistry expert. Why, then, are you trying to provide an explanation for something youobviously don't understand? 216.41.78.78Mercury42

KOH + Li

^^ I think what he was implying is "isn't Li more reactive than K?" I'm no chemistry expert though.

No. Reactivity increases as one goes down group one due to increasing size of atom and a weakening hold on the outermost election. The most reactive is therefore Francium. But that is a very uncommon element indeed. This table reflects common elements and this is what is commonly taught (in UK schools at least). --LukeSurl 18:40, 10 October 2005 (UTC)[reply]

I believe that LukeSurl is right, however, I searched other websites. [1]Give me confusing results, even the equasion they used at the start for examples. I thought Zinc could only react in acid, and not water. Clarification anyone?

This series definitely is wrong. Li should be at the top (http://www.unr.edu/sb204/geology/mas.html). I think there are other errors too.--gregory.brockman

Don't belive everything you read. This rather page from the BBC [2] would suggest otherwise, as well as a host of other pages. It appears there is a US-UK thing going on here. US pages suggest a Lithium headed table whilst UK pages a Pottasium headed one (though there are exceptions in either case). It would appear that it depends upon how one defines the series.

Some searching reveals that the UK tables are defined by displacement reactions and the US ones upon Standard electrode potential as the list corresponds exactly with that of Table_of_standard_electrode_potentials.

Thus for the considerations and qualifiers given in the article, which I will now reinforce, the Potassium table is applicable--LukeSurl 13:11, 29 March 2006 (UTC)[reply]

I think I have to say silver reacts with acids, so why is it not higher on the table?

Reeactivity

I think this statement needs more clarification.

Metals with a greater total number of electrons tend to be more reactive as their outermost electrons (the ones which will be lost) exist further from the positive nucleus and therefore they are held less strongly.

For instance, Lead has more electrons than Lithium, yet Lithium is more reactive. I suggest this phrasing.

Heavy metals tend to have their valence electrons in a shell further from the nucleus, so tend to give them up more easily because the nucleus imparts weaker attractive force on them.

Reactivity level

There should be a reactivity number. The reactivity number range from 0-5 or 0-10. Cosmium 23:55, 29 January 2007 (UTC)[reply]

UK v. US Tables

Could we display both the UK and the US versions of the table? And which one is currently displayed? --SuperCow 17:02, 21 February 2007 (UTC)[reply]

Explain the difference between REactivity and activity

I am a high school chemistry student (in america) and this table of reactivity is very different from the activity series in our text book, which is what we use to determine if a single-displacement reaction will occur or not. For example, in our textbook lithium is above potassium as others have stated above.

Could you add a line of clarification on this topic please?

Also it might be helpful to say more that just "reacts with water" and "reacts with acids." Mg, Al, Mn, Zn, Cr, Fe, and Cd all will react with steam. Additionally Sb, Bi, Cu, and Hg react with oxygen while Ag, Pt, and Au do not. This may be obvious to you, but for the rest of us it would be helpful if someone could add it to the table.

Thanks. —The preceding unsigned comment was added by 71.202.10.187 (talk) 05:45, 23 February 2007 (UTC).[reply]

Technicalities

There were some revisions made to the table by an anonymous user which were then reverted by User:Vsmith. I believe that those revisions made by the anonymous user were more correct than what was previously listed. The version I am speaking of can be found here. [3]. I'll have to look it up, I'm not positive about it. --SuperCow 16:58, 10 April 2007 (UTC)[reply]

I believe that version was more accurate- this has been said by another user, and i agree:

"Also it might be helpful to say more that just "reacts with water" and "reacts with acids." Mg, Al, Mn, Zn, Cr, Fe, and Cd all will react with steam. Additionally Sb, Bi, Cu, and Hg react with oxygen while Ag, Pt, and Au do not. This may be obvious to you, but for the rest of us it would be helpful if someone could add it to the table."80.240.197.170 10:15, 3 July 2007 (UTC)[reply]

Carbon

If we have put Hydrogen in this, why havent we put carbon in the reactivity series?

Calcium

i believe the periodic table shown is the UK version, and i am using a UK book, but it says that Lithium (Li)is before (more reactive) than Calcium(Ca)- so which is right?80.240.197.170 10:14, 3 July 2007 (UTC)[reply]

New opinion on Lithium issue

http://antoine.frostburg.edu/chem/senese/101/redox/faq/activity-series.shtml

I found useful information here,

""

It might be expected that metals with lower ionization energies and lower electronegativities would be more active, since they would be expected to more easily lose electrons in a displacement reaction. But while ionization energy and electronegativity do affect a metal's ranking in the series, other factors have a strong and complex influence on relative activity

""

Hope it may help to solve our problems

The potassium-lithium issue explained.

I am not a professional metals chemist either (actually a high school student), but I thought that it might be helpful to give an explanation of why there is an argument concerning whether K or Li should be at the top of the chart. Potassium metal is indeed more reactive than lithium metal, because potassium has a more loosely bound valence electron. In direct reactions, potassium reacts more violently than lithium. In aqueous solution, lithium is indeed the species with the most negative reduction potential, but this is due to the fact that the lithium ion has a very high charge density and this results in a more negative free energy of hydration. The reason, however, that potassium will burst into flame when it contacts water whereas lithium only fizzes is that potassium has a lower melting point (due to its loosely bound electron) and the heat of reaction will melt the potassium, which increases the rate of the reaction. This shows that things are often more complicated than we can anticipate in science. (As if to complicate things further, potassium is produced from KCl using sodium; sodium should be less reactive, but the greater volatility of K compared to Na drives the equilibrium Na + KCl -> NaCl + K to the right, in accordance with Le Châtelier's Principle.) As for whether K or Li should be at the top of the chart, the aqueous potentials are more or less useless for making a decision since adding Li to a solution of KCl will not displace K anyways since the Li will react with water instead, due to its higher reduction potential. For this reason I believe that K should remain on the top of the chart.

And as an aside, why is everyone so concerned with the K-Li argument and ignoring the Au-Pt one at the bottom of the table? After all, although gold has the higher reduction potential, platinum is much more difficult to oxidize than gold, and it dissolves more slowly in aqua regia. However, platinum(IV) oxide is more stable than gold(III) oxide (which decomposes at 150° C), suggesting that platinum metal's inertness is probably only due to kinetic factors... Bbi5291 01:16, 26 August 2007 (UTC)[reply]

Need to add US version

Just to let everyone know, the British Empire no longer exists. There are other countries besides the UK. A US version is needed on the page to add other points of view. Otherwise, this page is restrictive and only applies to countries that use the UK version of the activity series. Keep the UK version, though. 71.111.76.124 (talk) 16:12, 4 February 2008 (UTC)[reply]

And how about a referece for this supposed U.S. version? A link to one single State where it is taught that lithium is more reactive than potassium, or that calcium is more reactive than sodium? Physchim62 (talk) 09:48, 5 January 2009 (UTC)[reply]

Definitions, Carbon, ect

There are definitions of "reaction", and should be included. The reason hydrogen is included is that hydrogen can be a cation or an anion. This is not true for carbon. From my knowledge, there is only 1 version of the activity series. —Preceding unsigned comment added by Dillz42 (talk • contribs) 03:41, 3 February 2009 (UTC)[reply]

Transformers?

Who put that thing about transformers in there?