Alkali Metals - Gain, lose, or share valence electrons?
831195
lose\n\nLook at your periodic table.  Ithose on the left two columns lose.  Those in the last two prior to the noble gases gain.  The others can do either but generally speaking if they have less than 4 valence electrons they lose and if the have more than 4 they gain.  If they have four such as Carbon and silicon, they can do either.  This makes for some very neat chemistry for those elements.
12366
Hi again,\n\n    Well you see, as you know electrons are added up in the 3d orbital in galium, right? So with the increase in number of electrons, the no of protons i.e atomic number also increases. So now the outermost p electron in Al is attracted by 13 protons. But that in galuim is attracted by 31 electrons. So the force of attraction is much more. Now in other atoms, these outer electron attraction is balanced by counter electron electron repulsion. But the added d electrons  cannot shield the outer p electrons much from the force of attraction of the highly charged nucleus. This is similar to the reason why the transition elements contract on increase in at no. Other examples are lanthanide and actinide contractions. If you still dont get it,\nmeet me on Yahoo Messenger. My id is jchemisch. I will talk to you about it. All the best. Hope i can help you if you need!!
641799
It depends on the octet rule. If the element fulfills its octet, or has 8 valence electrons(such as the noble gases) then it will be very stable. The farther they are from fulfilling the octet rule, the less stable the element is.
476212
Atoms want to be like a "noble gas" with a filled outer shell.  I think it has to do with being in a stable state.  For Mg, it's a lot easier to drop 2 electons to look like Ne rather than gain 6 to look like Argon.\n\nThis very basic premise only works for things on the "sides" of the table.  The transition elements in the middle are a bit different.
233865
Generally, the elements that form ionic bonds tend to have either very high or very low electronegativity. This means the Alkali metals, Alkaline Earth metals, and the Halogens, especially when reacting with each other.
207266
Alkali metals and alkali earth metals tend to form ionic bonds.  They have a +1 or +2 charge.\n\nThe halogens normally form ionic bonds when "joined" with a IA or IIA metal.\n\nTransition metals normally are ionic.\n\nNow for the trick part:  Carbon and nitrogen generally form covalent bonds.  When joined with other elements, they can produce a neutral molecule (CO, CO2).  But they also form polyatomic ions (C03- (carbonate); NO3- (nitrate) ).  \n\nGeneral rule of thumb - IA, IIA, and VIIA atoms will make ionic bonds.  \n\nHope this helps!
218524
In Ionic bond, elements looses or gains electron(s) and become ions and the electrostatic potential of these ions bind them\n\nIn covalent, the participating elements are bound by sharing electrons between them.
178276
Gain one/two electron(s):\n\nIf an atom or ion acquires another electron in a chemical reaction, it has gained an electron.  ditto for two electrons.\nExample: S has 16 electrons.  If it gains one electron it becomes a S- ion.  If it gains two electrons, it becomes a S-2 ion.\n\nSteal one/two electrons:\nIf an atom or ion looses an electron in a chemical reaction, it had to go somewhere.  That "somewhere" will be to another atom/ion.  So, the receiving atom/ion could be said to have stolen the electron.  Same goes for reactions involving two electrons.\nExample: Na reacts with Cl to produce NaCl.  Cl "steals" an electron from Na, creating Na+ and a Cl- ions.\n\n"Never ever react electron"\nI have never ever heard this phrase.  Maybe it refers to a species (atom or ion) that does not participate in the reaction.  It's valence electron(s) would not react.
706309
You want an atom that is easy to take one electron from, but hard to take a second.\n\nRemoving an electron from Sr or Mg would give them a configuration isoelectronic with the alkali metals.\nWhich don't hold onto their electrons very well,  and would have low ionisation energies.\nSo it's not a) or b).\n\n\nRemoving an electron from Na or K would give them a configuration isoelectronic with the noble gases.\nWhich would require a lot of energy to get the second electron from.\n\nHmm sodium or potassium ...\n \nSodium is a smaller atom than potassium, so it holds its valence electron tighter, and more energy is required to remove it.\nBut once it is isoelectronic with neon, it will have a much higher ionisation energy because it will be so much smaller.\n\nPotassium's first ionisation energy is lower than sodium's, but the second ionisation value (when it is isoelectronic with argon)\nwill be lower than the sodium ion's, when it is isoelectronic with neon.\n\nI'm going with sodium.
46910
I'll make it easy for you.All the metals forms positive ions by losing electrons and all non-metals form negative ions by gaining electrons.\nExample:- NaCl  Na+ & Cl-
1092996
Atoms become more stable with a full valence shell of electrons (usually 8 electrons).  Therefore, if an atom has 7 electrons, it is going to try to gain 1 more electron to gain a full valence shell.  Likewise, an atom with 1 electron on it's outer shell is likely to lose that electron, since the shell beneath it is full.  Since these atoms are losing or gaining electrons, they give themselves a positive or negative charge as a result and become ions.\n\nThe transition metals are a completely different story however, because these deal more with the d-orbitals rather than just the s- and p-orbitals.
991396
A potassium ion has one positive charge because it is missing one valence electron.   So K can form compounds with anything that is electronegative; in other words, any atom or molecule that likes to grab electrons. Anything at the right hand end of the periodic table, like O, S or the halogens for instance.   Or a more complicated compound would be with an organic acid like stearic acid; you replace one H with a K and you get a liquid soap.   If you used Na instead of K you'd get the usual solid soap.   When I was a kid in Britain, the soap in public bogs was liquid so you couldn't steal it.
916600
Ionic compounds try to achieve the same thing...only instead of atoms sharing electrons with other atoms (co-valent) in a chemical bond, Ionic compounds achieve lowest energy configurations by receiving, or giving up, electrons.  For example, the sodium atom has one electron in it's valence "shell" and will give it up (becoming positively charged in the process) in order to have the same electronic configuration as the previous noble gas (neon) and becomes the sodium cation.\nFluorine, having seven electrons in it's valence shell would rather accept and electron (to have the neon electron configuration) and becomes the negatively charged fluoride anion.
491001
Homework, huh?\n\nWell, it's because K+ contains more electrons than the Na+. Which means that K+ has 3 layers of electrons (filled in the 1s2 2s2 2p6 3s2 3p6) while while Na+ has only 2 layers of Electrons (1s2 2s2 2p6)
783373
This depends on how many electrons the element has to lose or gain to complete its outer layer. If the element is on the right side of the periodic table then it will gain electrons. The left side will lose electrons. How many electrons can be determined by how far away the element is from the nearest side of the periodic table.\n\nTHere is of course more technical depth to this however this thumb rule will do. For more info type ionisation into wikipedia. that should help...
152932
alkaline earth metals are group 2A in the periodic table, they are Be, Mg, Ca, Sr, Ba, Ra.\nhalide is the name of salt that has halogen group (group 7A).they are F, Cl, I, Br, At.\nSince the valence of alkaline is 2 and that of halogen is 1, we'll have this chemical formula: MX2 (can't type subscript :P ) (2 should be typed in subscript).\nFor example: MgCl2, MgI2, BaCl2, CaBr2,....
697038
This is kinda hard to draw on here...\n......_\nK--Br|\n......_\n\nThe lines around Br represent 2 electrons, and the -- represents a bond...ignore the periods