5 Responses

1. Gary

   15|Mar|2008 1

   Answer should be A.

   When ionic cpd is formed,its stable.

   Reply

2. Jennifer

   15|Mar|2008 2

   Yes. I agree with Gary.

   Calcium has 20 electrons. It is a group II metal

   When it forms an ionic compound, it lose 2 electrons readily to obtain the octet/noble gas configuration for it to become stable.

   Calcium metal becomes a cation with charge 2+

   Hence, electronic configuration: 2.8.8

   Reply

3. sean

   17|Mar|2008 3

   Well Done Gary & Jennifer.

   The explaination given by both of you are correctly described.

   You should be able to answer Section B and C questions for such Ionic Bonding
   topic with ease.

   Keep up that tempo!

   Cheers
   Sean

   Reply

4. abedelfeta

   24|Mar|2008 4

   dose ionic compuonds have dipole dipole atrction?

   Reply

5. sean

   26|Mar|2008 5

   Hi Abedelfeta,

   I suppose you are from a higher education level than GCE O Level Sec 4/5 or US
   Grade 9-11 since they do not really learn about Dipole Dipole Attraction.

   For GCE O Level standard, i would like to state that dipole-dipole is the ’same’ as
   Ionic Bonding. This is to make sure they are not confused with new chemistry
   terms that are not tested.

   But in reality and higher education, Dipole-Dipole is only Similar to Ionic Bonding,
   this meaning that they are different.

   Ionic Bonding occurs when there is one element that loves to give electrons away (i.e. Grp 1 metal) and an element that loves to
   take in electrons (i.e. Grp 7 halogens). There is a distinct and specific electron transfer from one element to another.

   In dipole-dipole, the two elements do not have High tendency to lose and gain an
   electron. Instead, there is slight amount of sharing within the 2 elements.

   Detailed explaination can be seen at: http://web.mst.edu/~gbert/INTERACT/intermolecular.HTM

   Hope that helps,
   Sean

   Reply