IF ATOMS ARE STABLE, WHY do THEY FORM IONIC BONDS?

the second part of ur qn is the right one. if an atom has diff no. of protons and electrons, it is an ion and inherently very very unstable. COMPARED to them, a Na atom is stable. but then any atom will always try to have an octet in its outermost shell. Hence Na has a really high affinity for any atom that will help it to complete the octet. Hence the reaction with Cl

it is not actually electrostatic attraction. if it were electrostatic attraction alone, no atom would ever bond with any other atom since both have negatively charged electrons in their outermost shell and so they would repel each other. However the atom's thirst for an octet is strong enough to overcome this repulsion to some extent and the minimum energy state is found at some particular distance between the nuclei, which is called BOND LENGTH.

Na+ and Cl- ions are found only in the crystal structure and in ionic solutions. My explanation is for Na and Cl ATOMS.

Hi brainblob,

Does GCSE mean geoscience, by any chance? It turns out I'm a geochemist, so I just thought I'd ask. : )

Anyway, here's a way to think about your question that I hope will help. To say whether an atom is stable or not stable doesn't really have any meaning, because this is relavitive. An atom can be stable RELATIVE to something else, or not stable relative to something else, but this is all we can say. Here's how the relative stabilities of the atoms in this situation would work out:

When we remove an electron from a Na atom (since we're talking about NaCl in this example), it takes energy to do this. But because of the quantum mechanical properties of a Na atom (aka, it is still fairly stable when it has only completely full or completely empty electron shells), it takes only very little energy to do this. In the same way, placing that electron into a Cl atom to form a Cl- ion takes a little energy because you are putting that electron into a sea of other electrons (and negative charges repel). So, moving the electron and forming a pair of ions takes a little energy input.

However, since we now have two oppositely charged ions, they are attracted to each other and the process of bringing them close together releases A LOT of energy. So even though forming the ions cost us some energy, we get a whole lot of energy BACK by forming the ionic bond and the net result is that the Na+ --- Cl- bond is a much more stable configuration than separate Na and Cl atoms. That's why the Na and Cl will bond to each other.

So it's not a matter of the Na atom being stable or not stable, it's a matter of a bond between two ions being MORE stable than two separate atoms. Now of course, if you do not get enough energy back in forming the bond, then the process will not happen at all and you will be left with two separate atoms. It all depends on which two atoms you're talking about, and what chemical conditions you're under.

As far as your next question, I assume you're talking about electron configurations. This is something that is not terribly complicated, but would be VERY hard to explain in writing. Basically, there is an order to remember in filling subshells, and you simply take the total number of electrons in the atom, and fill the subshells in the correct order until there are none left to place. There a few exceptions to this rule, and they are all found in the transition metals... the s-block and the p-block of the periodic table will always follow the normal order. But as I said, I would have to write a chapter to fully explain this, so it's best to just try it on your own using whatever book you're working out of, and ask questions if you get stuck.

Hope this helps you! Have fun with your chem class.

The word stable is rarely helpfull I'm afraid.

What you are saying in the third paragraph is close to the truth. All atoms/ions want a full outer shell, to do this sodium needs to lose an electron and become Na+ it can do this by forming an ionic bond with a group 7 element like chlorine.

Hopefully you will do some experiments where you look at group one metals at GCSE, you can see from sodiums reactions with water it is not what you might call "stable", NaCl is the main constituent of table salt however and is more "stable" but if you dissolve it there are still some reactions it can take part in.

In terms of the last tip you ask for the number of electrons in an elements outer shell is the same as the group it is in (this is true for the first 20 elements untill the transition metals start but you only worry about the first 20 at GCSE, at least you did two years ago when I did it, the only other exception is helium. It has 2 electrons in its outer shell but because this is the first shell and is therefore full it is generally thought of as inert (or even stable :-P) and so is put in the same group as the noble gases.

Firstly not all atoms are completely stable. That's why radioactive elements such as Uranium decay into more stable elements such as lead.

In the case of Sodium and Chlorine, both elements are stable but they are able to react together (and with a lot of other things) by donating or receiving electrons in their outer orbitals so that they acquire the stable configuration of one or other of the inert gases. This is an IONIC bond as distinct from a covalent bond where the electrons are shared.

In the case you have given, Sodium donates its outer electron (it's only got one) to a Chlorine atom which has seven electons. In this way the sodium atom becomes a positively charged ion and the acquires the configuration of the inert gas Neon and the Chlorine atom becomes a negatively charged ion and acquires the configuration of the inert gas Argon.

The two atoms in Sodium Chloride are joined together to form a stable compound by an ionic bond but it's relatively easy to separate them by electrolysis for instance.

Ions themselves are only normally stable if they are either held in a stable compound or dissolved in a suitable liquid-normally water which is partially ionised itself-where the ions are stabilised by interaction with the water molecules.

For every negatively charged ion (such as a Chlorine ion) you will normally find a positively charged ion (such as a Sodium ion or a hydrogen ion from the water) otherwise the solution will acquire a net charge.

In the absence of a suitable liquid to stabilise them any free ions will try to combine with anything they come in contact with-particularly if it's got an opposite charge.

It's a bit difficult to explain but I hope this helps

Yes, Na is not stable. Only atoms of the group 0 (noble gases) are stable. Na will react with some other element to gain a full valence shell. You are right about ions part. The oppositely charged ions attract each other and they form sodium chloride.

Because, all atoms want to reach the electron configuration of the noble gas nearest to them on the periodic table. So they either send or receive an electron(s) from another atom(s).

There are two kinds of ions, cation (positive charge), and anion (negative charge). Elements that form cations are metals and they lose electrons. Elements that form anions are non-metals and they gain electrons. Nothing happens to the protons, chemistry is all about electrons.

The whole goal of this is to achieve the electron configuration of a noble gas, because they are the most stable elements (hence the reason they are nonreactive). By giving away electrons, the cation can achieve the config. of a noble gas and teh anion can too.

an atom is the smallest particle of an element that can take part in chemical reaction.if all atoms are stable,then this is definitely wrong.atoms of all element are unstable except for those in Group 0.noble gases do not form bonds becaus their bonding shells are full,and all their electrons are paired.so,they are stable.other atoms form bonds so as to achieve the stable configuration of these noble gases. A sodium atom is unstable ,as it has 1 electron on its outermost shell.when it loses that electron,and now has 8 electrons outside,it becomes stable.

In the example of NaCl, both are stable. The atoms don't react TO each other, they bond WITH each other.

Each atom strives to have a full outer shell, so in order to do that, they must sometimes share electrons with another atom. They are both quite stable on their own.

Hope that helps??

metals have one tow or three electrons in their outer shell and as

the goal for atoms is to have complete shells

and non metals usually are short of one or two or three electrons in their outer shell

so when they get together electrons are exchanged

metals lose them and non metals gain them this is making an ionic bond as ions are formed

metals los electronsand non metals gain them

they are more stable in this state and are hard to break up by heating

but do break up into their ions in water when they dissolve in it to for a solution

Ionic bonds are betwean ions ... which form when electrons are lost or gained

use OIL RIG to help

Oxidation Is the Loss of Electrons (the ion is less -ve or more +ve)

Reduction Is the Gain of Electrons (the ion is more -ve or less +ve)

unstable atoms react radioactivly (the nuclious of the attom not the electrons)