Thread: reactive metal

Can anyone tell me the most reactive metal on earth?

Sodium; it reacts readily with water.

Originally Posted by CircularlyPolarized

Sodium; it reacts readily with water.

Lithium reacts even more readily with water.

Right, forgot about lithium.

Originally Posted by DivideByZero

Originally Posted by CircularlyPolarized

Sodium; it reacts readily with water.

Lithium reacts even more readily with water.

Are you sure about that? Because the reactivity of the alkali metals in Group 1 increases as you go down the column. For example, Rubidium is more reactive in water than Sodium is. Just going with the reactivity of the alkali metals, I'd say Francium might be the most reactive metal, but I don't know for sure.

Originally Posted by Chemboy

Originally Posted by DivideByZero

Originally Posted by CircularlyPolarized

Sodium; it reacts readily with water.

Lithium reacts even more readily with water.

Group 1 increases as you go down the column. For example, Rubidium is more reactive in water than Sodium is. Just going with the reactivity of the alkali metals, I'd say Francium might be the most reactive metal, but I don't know for sure.

thanks for yr answer, so what about the second column?

Originally Posted by icu

Originally Posted by Chemboy

Originally Posted by DivideByZero

Originally Posted by CircularlyPolarized

Sodium; it reacts readily with water.

Lithium reacts even more readily with water.

Group 1 increases as you go down the column. For example, Rubidium is more reactive in water than Sodium is. Just going with the reactivity of the alkali metals, I'd say Francium might be the most reactive metal, but I don't know for sure.

thanks for yr answer, so what about the second column?

The second column is the alkaliNE earth metals. They're also very reactive (including with water), but not quite as much, probably because they possess a filled orbital and subshell in their valence shell...

cool thanks, but why do some metal react to water like sodium and some dont??

usually it depends on the relative stability of the product and reaction. and the activation energy of the reaction.

if the product is more stable than the reactants a reaction will usually occur. In this case we say the reaction is thermodynamically unstable.

However in some cases the reaction activation energy (energy required to make the reaction happen) is too high, this means the reactants are kinetically stable. so the reaction will not occur or happen slowly.

this is why rusting is such a slow process.
Iron + water + air -------> iron hydroxide

high activation energy so happens slowly

wow, thanks heaps for clearing it out :-D

Off the top of my head I can't think of anything more highly reactive than the actinoids and lanthanoids. These are known elements, but what about stuff in the heart of the sun?

umm :? i dont know

thanks

Originally Posted by DrCWho

Off the top of my head I can't think of anything more highly reactive than the actinoids and lanthanoids. These are known elements, but what about stuff in the heart of the sun?

Dunno about the actinides and lanthanides, but I'd suspect that in the heart of the Sun, energy levels are too high to allow for chemical reactions. Nuclear only, is my guess.

Haven't you heard? The Sun is made of solid iron, or calcium ferrite.

The surface crust of the sun is mostly made of iron. It is likely however that the surface varies in iron content from one part of the crust to another. Parts of the surface may look much like the fragment above, while other regions along the surface may contain more iron and look like the fragments below

http://www.thesurfaceofthesun.com/

Originally Posted by Bunbury

Haven't you heard? The Sun is made of solid iron, or calcium ferrite.

The surface crust of the sun is mostly made of iron. It is likely however that the surface varies in iron content from one part of the crust to another. Parts of the surface may look much like the fragment above, while other regions along the surface may contain more iron and look like the fragments below

http://www.thesurfaceofthesun.com/

Ooooooh. You had me going for a bit. At first glance I'd say it isn't a spoof, but a conspiracy theory site.

Thanks for that.

Actually both Doppler IR readings and a lot of math concerning the equation of state indicate there are cooler areas of the sun. Check the SOHO site (not the "iron sun" site).

Imagine how warped time would be inside the sun. the surface gravity is 28 G's. Time is slower inside the star. How much slower? In some zones closer to the core, it is 100,000 years behind us. Any elements produced in those areas would not reach the earth for quite some time depending on how many billions of years it would take for any traces to escape that gravity zone.

Naturally that is quite a stretch of the imagination.

Actinides and Lanthanides are the "rare earth" metals including uranium, plutonium, and all that. Last time I check U235 was the most reactive heavy metal we know as of now.

the surface gravity is 28 G's. Time is slower inside the star.

Isn't gravity greatest at the surface, and decreases towards the core? Then time should be slowest on the surface and increase as you move either up or down.

Originally Posted by Bunbury

the surface gravity is 28 G's. Time is slower inside the star.

Isn't gravity greatest at the surface, and decreases towards the core? Then time should be slowest on the surface and increase as you move either up or down.

With one proviso, though: in a non-solid object, if the density increases closer to the core, then the overall force due to gravity can increase too.

With one proviso, though: in a non-solid object, if the density increases closer to the core, then the overall force due to gravity can increase too.

Still, at the very center the force of gravity must be zero, so the gravity profile from surface to center might increase then decrease. There should be a maximum at some distance below the surface.

Originally Posted by Bunbury

With one proviso, though: in a non-solid object, if the density increases closer to the core, then the overall force due to gravity can increase too.

Still, at the very center the force of gravity must be zero, so the gravity profile from surface to center might increase then decrease. There should be a maximum at some distance below the surface.

That's what I would guess too - unless, of course, it has a micro-black-hole at it's centre...

It's density based, true, but not necessarily solids. Dense liquids seem more gravitic than fluffier stuff.

At the core of any solid created by spinning is a void or a comparative one. There's a strongest layer and this is the heart of that gravity.

Originally Posted by Chemboy

Originally Posted by DivideByZero

Originally Posted by CircularlyPolarized

Sodium; it reacts readily with water.

Lithium reacts even more readily with water.

Are you sure about that? Because the reactivity of the alkali metals in Group 1 increases as you go down the column. For example, Rubidium is more reactive in water than Sodium is. Just going with the reactivity of the alkali metals, I'd say Francium might be the most reactive metal, but I don't know for sure.

Francium is one of the most reactive metals. Not sure about THE most (probably is), but certainly of the alkali metals it is. In fact it's so reactive, it reacts explosively with common amounts of water vapor in the air. For that reason it has to be stored in oil....even then it eventually reacts away.

Interesting.........

In fact it's so reactive, it reacts explosively with common amounts of water vapor in the air. For that reason it has to be stored in oil....even then it eventually reacts away.

but not quite correct. The Fr-Isotope with the longest half-life is 223Fr with exactly 22 MINUTES untill half of it has decayed. The shortest is something in the MILLISECOND range. It is formed as a intermediate of the Actinium- or Neptunium- decay. And in real life it is produce by firing protoms on Thorium. I'd like to see some of it stored under oil. Quite some Tcherencow radiation I assume. So no, there is no Francium stored under any circumstances in a lab. The overall amount of Francium in the Earth's crust is estimated to be 30 grams.

My apologies, chemisty never was my strong point I didn't realise Francium was actually radioactive, Perhaps I was thinking of Ceasium? Wiki has alot of interesting information about Francium (surprisingly) and I was reading through the article....apparently at any point in time there is no more than 30g of Francium existing naturally in the entire Earth's crust!

wow

I had to check the top post to be certain wwe weren't asking about what element reacts most violently with water. That wasn't asked. As for reactions without any added energy, i.e. fusion of hydrogen, then I still side with uranium as the most highly reactive of the known elements. It decays without any help. That is how Beckerel discovered radioactivity, when it exposed some film in a desk drawer beneath it.

Originally Posted by DrCWho

I had to check the top post to be certain wwe weren't asking about what element reacts most violently with water. That wasn't asked. As for reactions without any added energy, i.e. fusion of hydrogen, then I still side with uranium as the most highly reactive of the known elements. It decays without any help. That is how Beckerel discovered radioactivity, when it exposed some film in a desk drawer beneath it.

Since this is a chemistry forum, one can only assume the OP was asking about chemical reactivity. This is nothing to do with nuclear physics. In nuclear physics the term is 'radioactivity' not 'reactivity'.

Also, fusion of hydrogen or any other kind requires an input of energy...it doesn't happen spontaneously. Why? because in order for nuclei to fuse, the nuclear strong force must be greater than the electrostatic repulsion between nuclei. For this to happen, the nuclei need to be very close...and energy is required to overcome the electrostatic repulsion.

Nuclear fission also requires a small amount of anergy to take place, namely the firing of alpha particles.

Not to mention the fact that Uranium isn't the most radioactive. The shortest half-life isotope of Uranium is 68.9 years (U-232). As mentioned just a few posts above the longest lasting Fr isotope is 22 minutes. Wake up, Doc.

The point being made is that the periodic table defines a sufficient amount of data to deduce that the higher reactive materials are in the actinoids. Semantics of radioactivity vs. reactivity are really moot when we think of chemotherapy and moreso nuclear reactions.

Still picking at the "little" picture, are we, Harold? Go back to sleep.

Dr.CWho

DrcWho, yes the periodic table classifies elements according to their subatomic structure, and the heaviest elements become radioactive because there is simply too much concentrated like-charge in the nuclei to hold itself together. Indeed we do get an enormous amount of energy out of these nuclear reactions.

However I think it is important to note the difference between a nuclear reaction and a chemical reaction, not because I'm nit-picking, but because the mechanisms are quite different, and should be classified as such.


They are both 'reactions' of sorts (so is the force stopping you fall to the middle of the Earth, and so is this reply, if you look at it like that).


A nuclear reaction involves interactions/behaviour of the Nuclei of atoms, whereas a chemical reaction is only concerned with the interactions/sharing/behaviour of valence sheel electrons of the atoms, to from various types of bonds between atoms.

A nuclear reaction also converts small amounts of mass into large amounts of energy, as given by E=mc², and as seen in nuclear bombs/ fission reactors. In a chemical reaction however, mass is conserved....which is what the principle of balancing equations is based on....moreover nuclear structures of atoms are preserved, which allows us to say that the amount ,and types, of reactants used up in a chemical reaction, is equal to the amount and types of products produced....which is why we can balance equations.