Question

(i) Write the electron-dot structures for sodium, oxygen and magnesium.
(ii) Show the formation of Na20 and MgO by the transfer of electrons.
(iii) What are the ions present in these compounds?

Answer 1

1.part
Sodium .2.8.1
Oxygen .2.6
Megnesium.2.8.2
2.part Na.2.8.1×2
2.8.8.4
O 2.6
totel 2.8.8.8.4

MgO 2.8.8.2

Answer 2

Answer:

When the valence electrons are represented as dots circling the elements it is known as the elemental structure with electron –dot.  

Thus for option i) we can write Sodium (2, 8, 1) = Na with one electron at the top. Again for Oxygen (2, 6) = O with two electrons each on three sides.

For Magnesium (2, 8, 2) = Mg with two electrons on the top.  

The formation of Na20 and MGO can be written as Mg2+ + O2 (2-).

In Na2O, Na+ and O2- ions are present and in MgO, Mg2= and O2 (2- ) ions are present.