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    (Original post by Sahir)
    For Pi / Sigma bonds, know a definition for each, that's all really.

    Pi = molecular orbital formed as a result of the lateral overlap of electron density in p-orbitals of adjacent atoms. Perpendicular to plane of sigma-bonds.. hence why you get geometric isomers of alkenes and electrophilic addition due to exposed electron density.

    Sigma = molecular orbital formed as a result of the side-side overlap of electron density in s-orbitals (tecnically they're hybridised) of adjacent atoms.
    my definition of sigma = It is a bond formed as a result of a head-on overlap between two orbitals, forming an electron density on the line between the nuclei.

    pi = It is a bond formed as a result of side-ways overlapping of two p orbitals, forming an electron density above and below the line between the nuclei.
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    i am Not sure that sigma bond is formed from side-side overlapping .. what i know is that its formed from head-head overlaping and Pi is formed by sideways or Bilateral overlapping .. and that sigma bond is stronger than pi becuz sigma bond has more Overlapping [of the orbitals] than the Pi.Plus the Sigma is confined in the inter-nuclei axis howevere the Pi is dispearsed on the sideways of the nuclei.
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    Noble gases are unreactive, because all the electrons in their bonding shell are paired. I dont understand why berylium is reactive, because its electrons are too paired in its outer shell.
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    (Original post by FidoDiDo)
    i am Not sure that sigma bond is formed from side-side overlapping .. what i know is that its formed from head-head overlaping and Pi is formed by sideways or Bilateral overlapping .. and that sigma bond is stronger than pi becuz sigma bond has more Overlapping [of the orbitals] than the Pi.Plus the Sigma is confined in the inter-nuclei axis howevere the Pi is dispearsed on the sideways of the nuclei.
    Fair enough, head-on then.. essentially though, you know they overlap
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    (Original post by SIMZZ)
    Noble gases are unreactive, because all the electrons in their bonding shell are paired. I dont understand why berylium is reactive, because its electrons are too paired in its outer shell.
    hint:
    1s^2, 2s^2
    2,8,8,2
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    (Original post by Sahir)
    Fair enough, head-on then.. essentially though, you know they overlap
    i vote for head-on for sigma and sideways for pie
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    (Original post by z!D4N)
    hint:
    1s^2, 2s^2
    2,8,8,2
    Ok, i understand the octet rule and noble gases. But some elements do not obey the octet rule, e.g. PCL5. Thats what i dont understand, why dont they obey it?
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    (Original post by SIMZZ)
    Noble gases are unreactive, because all the electrons in their bonding shell are paired. I dont understand why berylium is reactive, because its electrons are too paired in its outer shell.
    Bonding occurs when an atom or molecule can rearrange their electrons to give a lower energy arrangement of electrons and nuclei than was previously present.. you get electrons being shared, transferred or rearranged in some way.

    Which particular reaction are you looking at?

    Beryllium, for example in BeCl2 is quite reactive due to the electron density of small Be+ cation distorting electron shells around the large anions. Sooo.. err yea.
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    HeHeHe

    Noble gases are unreactive, because all the electrons in their bonding shell are paired. I dont understand why berylium is reactive, because its electrons are too paired in its outer shell.
    there is a mistake here .. Berylium doesnt have a full outershell .. it has a full outmost SUBSHELL .. i.e S P D F and u know that :
    First quantum shell = contains one Subshell = S =Max 2e to fill the shell
    Second quantum shell = Contains 2 Subshells S and P =Max 8e to fill the shell
    Third quantum shell = contains 3 S P and D =Max 18e to fill the Shell
    Etc...

    a metal usually react to achieve a Full outmost electron shell [ or noble gas electronic Configuration ] .. so a FULL OUTMOST ELECTRON SHELL { so it loses 2 electrons to achieve a full outmost electron shell }not a full Subshell...

    NOTICE= a Full Subshell confers a partial stability thats why Beryllum has a higher Ionization energy than Boron
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    (Original post by FidoDiDo)
    HeHeHe



    there is a mistake here .. Berylium doesnt have a full outershell .. it has a full outmost SUBSHELL .. i.e S P D F and u know that :
    First quantum shell = contains one Subshell = S =Max 2e to fill the shell
    Second quantum shell = Contains 2 Subshells S and P =Max 8e to fill the shell
    Third quantum shell = contains 3 S P and D =Max 18e to fill the Shell
    Etc...

    a metal usually react to achieve a Full outmost electron shell [ or noble gas electronic Configuration ] .. so a FULL OUTMOST ELECTRON SHELL { so it loses 2 electrons to achieve a full outmost electron shell }not a full Subshell...

    NOTICE= a Full Subshell confers a partial stability thats why Beryllum has a higher Ionization energy than Boron
    thanks to everyone helping me out, i understand the thing i was getting at, thanks very much.
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    (Original post by SIMZZ)
    thanks to everyone helping me out, i understand the thing i was getting at, thanks very much.

    AnytimeZ
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    cheers to everyone, in partic sahir. thats just what i wanted to know about the hybridisation thing has i dont have any notes for it. thanks a million x
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    how does beryllium react with water and oxygen?
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    (Original post by z!D4N)
    how does beryllium react with water and oxygen?
    i Dont think that Beryllium react with water .. however with Oxygen .. all the group 2 elements Tarnish in air to form an Oxide layer.
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    (Original post by FidoDiDo)
    i Dont think that Beryllium react with water .. however with Oxygen .. all the group 2 elements Tarnish in air to form an Oxide layer.
    Yes, beryllium does not react with water. It does burn in oxygen to form beryllium oxide.
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    It doesn't react with water... it is the only group 2 element not to. Mg is oxidised by steam and the rest react with cold water to form hydroxides, but Be does not.
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    Yup .. reactivity increases down the group .. but guyz no one answered my ques :confused:
    whats is the macimum yield of each of these products when 58.5KG of sodium chloride are electrolysed as brine?
    a)yield of chlorine/Kg
    b)yield of hydrogen/Kg
    c)yield of NaOH/Kg
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    (Original post by FidoDiDo)
    Yup .. reactivity increases down the group .. but guyz no one answered my ques :confused:
    whats is the macimum yield of each of these products when 58.5KG of sodium chloride are electrolysed as brine?
    a)yield of chlorine/Kg
    b)yield of hydrogen/Kg
    c)yield of NaOH/Kg
    The reaction is essentially: 2NaCl+2H20-->2NaOH+H2+Cl2.
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    (Original post by Ralfskini)
    The reaction is essentially: 2NaCl+2H20-->2NaOH+H2+Cl2.
    So it will be like :
    40Kg of NaoH
    1 Kg of H2
    35.5 Kg of cl2


    ????
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    What is polarity? and how is it applied to ionic and covalent bonds/
 
 
 
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