Write the symbol for every chemical element that has atomic number less than 75 and atomic mass greater than 173.5 u.

Following are the chemical elements that have atomic mass greater than 173.5 u and atomic number less than 75.

1.  Lutetium
                  Atomic Number  =  71
                  Atomic Mass      =  174.97 u

2.  Hafnium
                  Atomic Number  =  72
                  Atomic Mass      =  178.49 u

3.  Tantalum
                  Atomic Number  =  73
                  Atomic Mass      =  180.95 u

4.  Tungsten
                  Atomic Number  =  74
                  Atomic Mass      =  183.85 u

Answer; carbon monoxide (co);

The bergeron process.