The wheel is said as the most important and the greatest invention of all times. The most important aspect of a wheel is that it made invention of many other objects easy. It became very easy to move larger objects.
The chemical formula for calcium chloride is CaCl2. Calcium chloride contains one calcium atom that is bound to two chlorine atoms. It has a molecular weight of 110.984.
The ionic formula of sodium chloride is NaCl. I'm not sure what is meant by structural formula, but there is one chlorine for each sodium atom in the ionic compound.