F.4 CHEM@USE頭20隻elements....!?

USE 頭20隻  elements .
   a  .   Name TWO elements which are obtained from fractional distillation of liquid air .
   b .    Why does argon consist of individual atoms instead of molecules of two or more atoma?
   c .    Carbon combines with element X to form a covalent compound with the formula CX2.
           i.)  To which group does X belong?
          ii.)  Draw an electron diagram for the compound, showing electrons in the outermost shells  
                only.
   d .    Element Y forms a nitrate which has the formula Y(NO3)2 .
           i.)  To which group does Y belong ?
          ii.)  Predict the formula for the oxide of Y .



2  the following table gives some information about W , X , Y and Z which represent particles of some
    elements . These particles are either atoms or ions .
        
    Particle    Mass NO.    Atomic NO.      protons      electrons      neutrons

     W             14                7                                  7        
     X                                  9                                  9                 10
     Y                                                    9              10                10
     Z                                                    10             19                20

   * 空白左個D係UNKOWN.

    a . W exisits as diatomic molecules . Draw an electron diagram for itsmolecule , showing electrons in
         the outermost shells only.
    b .  
         i.) What is the relationship between X and Y ?
        ii.) Suggest a chemical reaction in ehich X can change into Y .
    c . X can form a compound whit Z .
        i.) Draw an electron diagram for the compound .
       ii.) Calculate the formula mass of the compound .

USE 頭20隻  elements .
   a  .   Name TWO elements which are obtained from fractional distillation of liquid air .
oxygen and argon

   b .    Why does argon consist of individual atoms instead of molecules of two or more atoma?
argon has an ouetrmost electron with 8, so it is stable in nature with only a single atom and does not need to have molecules of two or more atoms.

   c .    Carbon combines with element X to form a covalent compound with the formula CX2.
           i.)  To which group does X belong? group 6

          ii.)  Draw an electron diagram for the compound, showing electrons in the outermost shells  
                only.
   ..            ..
:  X  : : C : : X :

   d .    Element Y forms a nitrate which has the formula Y(NO3)2 .
           i.)  To which group does Y belong ? group 2

          ii.)  Predict the formula for the oxide of Y. YO

[[i] 本帖最後由 magiyafeimo 於 2008-10-11 13:43 編輯 [/i]]

I  have one more question.

2  the following table gives some information about W , X , Y and Z which represent particles of some
    elements . These particles are either atoms or ions .
        
    Particle    Mass NO.    Atomic NO.      protons      electrons      neutrons

     W             14                7                 7                7                 7
     X              19                 9                 9                9                10
     Y              19                9                  9              10                10
     Z                                                    10             19                20

   * 空白左個D係UNKOWN.

    a . W exisits as diatomic molecules . Draw an electron diagram for itsmolecule , showing electrons in
         the outermost shells only.

. W .  
  ...
  ...
. W .


    b .  

         i.) What is the relationship between X and Y ? y is an ion of x
        ii.) Suggest a chemical reaction in ehich X can change into Y .
X + Na= y + (Na)+
   
    c . X can form a compound whit Z .
        i.) Draw an electron diagram for the compound .
i think z should have some error in the table, proton and electron differs so much like that? 10 and 19?

       ii.) Calculate the formula mass of the compound .

[[i] 本帖最後由 magiyafeimo 於 2008-10-11 17:20 編輯 [/i]]

[quote]原帖由 [i]magiyafeimo[/i] 於 2008-10-11 17:15 發表 [url=http://www2.3boys2girls.com/redirect.php?goto=findpost&pid=27270911&ptid=425946][img]http://www2.3boys2girls.com/images/common/back.gif[/img][/url]
2  the following table gives some information about W , X , Y and Z which represent particles of some
    elements . These particles are either atoms or ions .
        
    Particle    Mass N ... [/quote]



Z 's protons is 19

and the Q.bii 's formula is it?
X +  Na = Y + (Na)+
WHY?

and the electron diagram (a),I don't understand  what this mean?
. W .  
  ...
  ...
. W .
係唔係一個W既outermost shell有5粒electrons?

[[i] 本帖最後由 哇三次 於 2008-10-12 10:31 編輯 [/i]]

c .    Carbon combines with element X to form a covalent compound with the formula CX2.
           i.)  To which group does X belong? group 6

      
[color=Red]Why X is in group 6?[/color]


    ii.)  Draw an electron diagram for the compound, showing electrons in the outermost shells  
                only.
   ..            ..
:  X  : : C : : X :


X has  6 electrons in the outermost shell?
C has 4 electrons in the outermost shell?
[color=Red]I don't understant . -3-[/color]

[[i] 本帖最後由 哇三次 於 2008-10-12 17:47 編輯 [/i]]

Z 's protons is 19

and the Q.bii 's formula is it?
X +  Na = Y + (Na)+
WHY?
X變Y，變成anion多左粒電子
可以找group 1 的金屬俾佢1粒電子例如Na鈉



and the electron diagram (a),I don't understand  what this mean?
. W .  
  ...
  ...
. W .
係唔係一個W既outermost shell有5粒electrons? yes


if Z has proton of 19 then Z is not an ion
then its outermost electron is 1
then

   c . X can form a compound whit Z .
        i.) Draw an electron diagram for the compound .
[Z]+ [X]-

       ii.) Calculate the formula mass of the compound .
z's mass = 20 +19=39
x's mass = 9+10=19

compound=39+19=58

[[i] 本帖最後由 magiyafeimo 於 2008-10-12 18:28 編輯 [/i]]