My own chemistry questions....

[albertlee]

1, why most transitional metals are less reactive than metals??

 

2, how compound ions are formed? eg, why sulfer + water = acid?

 

Energy...

 

why do you obtain energy when bonds are formed??

 

how does energy exist as such?

 

Albert

[vrus]

how does energy exist as such?

 

 

I think the reply to that would be, ( well atleast in humans and living animals as far as I know ) a molecule called ATP (Adenosine Triphosphate) produced by respiration.

[Klaynos]

1' date=' why most transitional metals are less reactive than metals??

 

2, how compound ions are formed? eg, why sulfer + water = acid?

 

Energy...

 

why do you obtain energy when bonds are formed??

 

how does energy exist as such?

 

Albert[/quote']

 

1) Their electron shells are less accessable, by this I mean they require to lose or to gain more electrons in their outershell than elements in other sections.

 

2) I don't really know, not a chemest.

 

Energy exists in many forms in our universe, from kinetic energy (vibrations and the like) to photons which are "packets of wave"...

[j_p]

1' date=' why most transitional metals are less reactive than metals??

 

2, how compound ions are formed? eg, why sulfer + water = acid?

 

Energy...

 

why do you obtain energy when bonds are formed??

 

how does energy exist as such?

 

Albert[/quote']

 

A lower energy state is more stable; compounds react to form more stable forms; when they do so energy is released, generally in the form of heat.

 

Transition metal bonding electrons are in a different electron orbital than the metals, don't they? Something about the d orbitals ...

[albertlee]

why do you obtain energy when bonds are formed??

[insane_alien]

because when an atom is unbonded it is has a high potential energy but when it forms a bond with another atom it moves into a lower energy state. and the energy is released either in a photon, or as kinetic energy(heat)

[rthmjohn]

The process of forming bonds is exothermic, thus releasing energy as heat. The process of breaking bonds requires energy. The combustion of methane for example (CH4) requires energy to break each of the for C-H bonds (research bond enthalpy) but the formation of C=O and H-O bonds releases more than is required to ignite the substance. Thus, the overall reaction is exothermic.

[YT2095]

there ARE Endothermic reactions however, but since many of these compunds are dangerous, I`ll refrain from submitting the ones I know of. there are some though

[albertlee]

1) Their electron shells are less accessable, by this I mean they require to lose or to gain more electrons in their outershell than elements in other sections.

 

????

 

not very clear.....

 

any one?

[akcapr]

barium OH and ammonium chloride or nitrate- the reaction is endothermic. since yt couldnt say.

[YT2095]

a rough way to put it is this, in the S group they only have 1 or 2 outer electrons, they`re quite easy to combine with other elements that are nearly complete but lack only 1 or 2 electrons to make something stable.

 

the D block is a middle ground, go to the right and it becomes electro Negative, to the left and it`s electro Positive.

 

ther`yre the least reactive because they`re more of less middle ground, and take more energy to "Sway" them one direction or the other.

 

the S and P block elements are already at or Near to, the extremes.

 

 

this is only Simplification of it, but should be enough to give you a "Feel" for the table of elements

[Klaynos]

????

 

not very clear.....

 

any one?

 

 

Electrons form in atoms in "shells". Atoms 'prefer' it for their outer shell to be full. There are two was of achiving this if they do not have a full outer shell, either lose all the electrons in their outershell and change which is their outer shell, or to gain electrons to fill their outershell. When you have one or two electrons in your outer shell or need one or two to fill it, this is quite easy to do so the element will be more reactive than one that needs to gain or lose a higher number say 4.

[albertlee]

to Klaynos, that's not relavant to the answer of why transition metals are less reactive than metals...and I already knew that..

 

to YT, what are P, S, D block you are talking about?

[j_p]

I actually got out my Inorganic Chemistry text for this [i thought I'd shot that thing years ago], and my general chemistry text, and my P-Chem Lab text, and I still can't find what I am looking for.

 

The d orbitals are actually of a higher enery level that the s orbitals of the next highest energy level; a 4s oribital is filled before the 3d orbital. And d orbital have more complex geometry.

 

But I can not find a simple explanation of why this means the transitionals are comparatively less reactive.

[DQW]

why do you obtain energy when bonds are formed??

 

 

Voila !

[YT2095]

to YT, what are P, S, D block you are talking about?

 

you`ll need to get yourself a periodic table for this, and also a highlighter pen.

 

the S block. you`ll need to draw a line down from where Ca and Sc touch down to where Ra and Ac touch. that section to the left of the line is the S block (write that above it).

 

now the D block goes right across to where Zn touches Ga, so from there draw a line down to where Hg touchesTl, all in That new sectioned space is the D block.

everything else to the right of that is the P Block.

 

now we could get fancy and insert the F Block, but that`s Off topic.

 

do the above, and you`ll know the S,D and P Blocks

[DQW]

????

 

not very clear.....

 

any one?

Consider Na (not a transition) metal. Each Na atom has 1 electron in the outermost shell. For Na to react' date=' it needs to have this extra electron ripped out. And after this electron gets pulled out, Na attains a very stable, Noble Gas configuration.

 

[b']The high stability of the end-product and the relative ease of getting there is what makes Na very reactive.[/b]

 

Now consider Fe (a transition metal), which has the configuration [Ar] 3d⁶ 4s². The best you can do with Fe is pull out 2 electrons to make it [Ar] 3d⁵ 4s¹ (both half-filled subshells) or 3 electrons, to make it [Ar] 3d⁵ (one half-filled subshell). So, you see that for Fe to react, you must (i) pull out more electrons, (ii) and still not reach the "most" statble configuration (only a local minimum). Removing all the 3d and 4s electrons takes too much energy, so Fe can really never attain a Noble Gas configuration.

 

The not-so-great stability of the end-product and the relative difficulty of getting there is what makes Fe not so reactive.

[Klaynos]

to Klaynos' date=' that's not relavant to the answer of why transition metals are less reactive than metals...and I already knew that..

 

to YT, what are P, S, D block you are talking about?[/quote']

 

Of course it's relevent, they are in the middle section with neither nearly full nor nearly empty outer shells so are less reactive than others.

[albertlee]

 

Voila !

 

the above is not very clear to me...

 

first of all, why potential energy??

 

secondly, can you explain in words??

[DQW]

the above is not very clear to me...

 

first of all' date=' why potential energy??

 

secondly, can you explain in words??[/quote']Have you covered electrostatics in physics ?

[albertlee]

well, I have heard that word... but I dont know it for one bit....

 

plz help

 

thx

[5614]

why do you obtain energy when bonds are formed??

I'll try and answer your question in simple terms without explaining electrostatics.

 

The answer is that before they bond you have two atoms floating around each with their own amount of energy.

 

When they come together and bond then they don't need all the energy from both of the atoms, that's 2 atoms worth of energy in 1 molecule, you don't need that much! So the atoms can release a bunch of energy.

 

OK, so this is technically floored, there are exceptions etc etc. but that is the real basic idea... if you understand what I said then you can try and understand the above posts.

 

To answer your "why potential energy?" question you need to learn about electrostatics.

[DQW]

to YT, what are P, S, D block you are talking about?

I'm more than mildly disappointed. I wish you'd pay more attention to the responses you get.

 

http://scienceforums.net/forums/showpost.php?p=179551&postcount=14

[j_p]

Consider Na (not a transition) metal. Each Na atom has 1 electron in the outermost shell. For Na to react' date=' it needs to have this extra electron ripped out. And after this electron gets pulled out, Na attains a very stable, Noble Gas configuration.

 

[b']The high stability of the end-product and the relative ease of getting there is what makes Na very reactive.[/b]

 

Now consider Fe (a transition metal), which has the configuration [Ar] 3d⁶ 4s². The best you can do with Fe is pull out 2 electrons to make it [Ar] 3d⁵ 4s¹ (both half-filled subshells) or 3 electrons, to make it [Ar] 3d⁵ (one half-filled subshell). So, you see that for Fe to react, you must (i) pull out more electrons, (ii) and still not reach the "most" statble configuration (only a local minimum). Removing all the 3d and 4s electrons takes too much energy, so Fe can really never attain a Noble Gas configuration.

 

The not-so-great stability of the end-product and the relative difficulty of getting there is what makes Fe not so reactive.

 

I would like to thank you for that clear and simple description.

 

But what about the geometry? Isn't it so that elements with electrons in d orbitals can form bonds at a wider variety of angles, and so that a wider variety of stable lattice formations are available? Or did I completely misunderstand Inorganic?

[albertlee]

I'm more than mildly disappointed. I wish you'd pay more attention to the responses you get.

 

http://scienceforums.net/forums/showpost.php?p=179551&postcount=14

 

 

well, at that particular time, I wasn't able to understand what you were saying...therefore I bypassed it, because I already got my answer from that thread......sorry..