1. 1. Sodium iodide and magnesium oxide are ionic compounds. Iodide and oxygen are covalent
molecules. Draw dot-and-cross diagram for:
i. Sodium iodide
ii. Magnesium oxide
iii. Iodide gas
iv. Oxygen gas
2. A. Draw dot-and-cross diagram for the covalent bond between carbon and sulfur. Show only
the outer electrons. Write the formula of the molecule formed.
b. draw dot-and-cross diagram to show the formation of co-ordinate bond between
phosphine, PH3, and a hydrogen ion, H+
, to form the ion PH4
+
. Show the co-ordinate bond
by an arrow.
3. Use electron dot diagrams to show the formation of ionic compound between the following:
a. Sodium and oxygen
b. Potassium and chlorine
c. Aluminium and sulfur
4. Draw the Lewis structure of the following compounds. Include all unshared electron pairs.
a. PH3
b. C2H4