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Topic: Can someone please help me with this piece of homework?  (Read 5234 times)

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Offline Kyleee

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Can someone please help me with this piece of homework?
« on: November 18, 2011, 04:43:28 PM »
A main group element "X" is known to bond covalently with fluorine to form a compound with molecular formula XF2. In this compound, both X and F obtain noble gas electron arrangements by sharing electrons.

1. To which main group of the periodic table is element X is likely to belong.

2. Draw a diagram to show how the outer electrons are shared to form the covalent bonds in a molecule of XF2.

3. Which noble gas does fluorine achieve the electron arrangement of in the compound XF2


I don't understand number 1 at all really, please explain. It says that it has two fluorine (F2), so how on earth can 2 fluorine elements bond with something else? Like, since fluorine has 7 outer electrons already, then if it bonds twice, it will receive another 2 electrons and therefore it won't get a full outer shell. Am I correct or am I just soooooo wrong? I don't get it at all, please help me.




Just to let you know, I will know number 2 is you tell me number one, but I'll still need some help with 3. So just help me with 1 and 3, please. :D

Also, When I said the molecular formula (XF2) the "2" is supposed to be a subscript.

« Last Edit: November 18, 2011, 04:56:48 PM by Kyleee »

Offline fledarmus

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Re: Can someone please help me with this piece of homework?
« Reply #1 on: November 18, 2011, 04:55:17 PM »
 Draw what you know so far - can you draw a dot diagram that has X making covalent bonds to two fluorine atoms, each of which has achieved a noble gas electron arrangements?

Offline Kyleee

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Re: Can someone please help me with this piece of homework?
« Reply #2 on: November 18, 2011, 05:04:11 PM »
Draw what you know so far - can you draw a dot diagram that has X making covalent bonds to two fluorine atoms, each of which has achieved a noble gas electron arrangements?
Well, I've just kinda thought about that for a minute, and what I was thinking was completely wrong. So answer 1 would be "Group 1"?

I picked group 1 because fluorine has 7 electrons on it's outer shell and group 1 only has 1 on it's outer shell. Which means it'll give the two fluorines complete outer shells.

Butttt, number three. how do I do that? Would it be neon?

Offline Kyleee

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Re: Can someone please help me with this piece of homework?
« Reply #3 on: November 18, 2011, 05:09:07 PM »
In fact, I've changed my mind. It's not group 1. It's group 6, right?

I picked group 6 because if I put group 1 then it's not going to give "X" a complete outer shell. But, if I pick group 6 and it bonds twice, "X" will receive two electrons, giving it a full outer shell.

Offline sjb

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Re: Can someone please help me with this piece of homework?
« Reply #4 on: November 18, 2011, 06:09:57 PM »
In fact, I've changed my mind. It's not group 1. It's group 6, right?

I picked group 6 because if I put group 1 then it's not going to give "X" a complete outer shell. But, if I pick group 6 and it bonds twice, "X" will receive two electrons, giving it a full outer shell.

Sounds good to me. So, what does the dot and cross diagram look like (just consider the outer shell for element X)?

S

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