Thermal Expansion.  best describes the increase in a materials volume 
        
                    
             
        
        
        
The US English System of measurement grew out of the manner in which people secured measurements using body parts and familiar objects. For example, shorter ground distances were measured with the human foot and longer distances were measured by paces, with one mile being 1,000 paces. Capacities were measured with household items such as cups, pails (formerly called gallons) and baskets.
        
             
        
        
        
If its atomic number is 48, then it has 48 protons in the nucleus 
of each atom.  Any more mass than that is supplied by the neutrons 
that are mixed in there with the protons.
If the mass is 167, and 48 of those are protons, then there are 
             (167 - 48)  =  119 neutrons
in each nucleus. 
        
             
        
        
        
The lens changes the focal distance of the eye so that you can focus on images/objects.