2f. The ionic bonding of the compounds magnesium sulfide and calcium sulfide
Doc Brown's Chemistry: Chemical Bonding and structure GCSE level, IGCSE, O, IB, AS, A level US grade 9-12 level Revision Notes
Example 2f. A Group 2 Alkaline Earth Metal combining with a Group 6 non–metallic element
* metals \ non-metals (zig-zag line)
Magnesium oxide MgO, magnesium sulfide MgS and calcium sulfide CaS will be similar electronically and give identical giant ionic lattice structures.
Group 2 metals lose the two outer electrons to give the stable 2+ positive ion (cation) and S and O, both non–metals in Group 6, have 6 outer electrons and gain 2 electrons to form 2– negative ion (anion).
For magnesium sulfide: Mg (2.8.2) + S (2.8.6) ==> Mg2+ (2.8) S2– (2.8.8)
For calcium sulfide: Ca (184.108.40.206) + S (2.8.6) ==> Ca2+ (2.8.8) S2– (2.8.8)
so both the magnesium/calcium and sulfide ions have a full outer shell like a noble gas
The dot and cross (ox) diagrams will be identical to that for calcium oxide above, except Mg instead of Ca (same group) and S instead of O (same group of Periodic Table). eg
The electronic dot & cross diagrams for the ionic bonding in magnesium sulfide and calcium sulfide
Lewis diagram for magnesium sulfide
Melting point of magnesium sulfide is 2000oC
electronic structure of calcium sulfide CaS
Lewis diagram for calcium sulfide
Melting point of magnesium oxide is 2525oC
All the formula highlighted in yellow can be described in the same way as magnesium oxide, magnesium sulfide, calcium oxide or calcium sulfide
The Group 2 Alkaline Earth Metal atom loses two electrons to form a doubly charged positive ion
The Group 6 non–metal atom gains two electrons to form a doubly charged negative ion
|Website content © Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Exam revision summaries & references to science course specifications are unofficial.|
Doc Brown's Chemistry
Enter chemistry SEARCH words e.g. topic, module, exam board, formula, compound name, type of reaction, chemical structure, concept, equation, phrase, homework question, any question on anything of chemical interest!
TOP OF PAGE