Strontium oxide is an ionic compound. Draw a diagram which shows its formula, the charges on the ions and the arrangement of the valency electrons around the negative
ion.
The electron distribution of a strontium atom is 2 + 8 + 18 + 8 + 2.
Use o to represent an electron from a strontium atom.
Use x to represent an electron from an oxygen atom.
(ii) Draw a diagram which shows the arrangement of the outer (valency) electrons in
one molecule of the covalent compound arsine.
The electron distribution of arsenic is 2 + 8 + 18 + 5.
Use x to represent an electron from an arsenic atom.
Use o to represent an electron from a hydrogen atom.