Fill in the blank answers please help.

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

Can someone me with questions 15 to 17 plz.

The image shows a process that releases nuclear energy which statement best identifies the process shown the process must be fusion because energy is released the process must be fusion because of have your nucleus formed a smaller nuclei the process must be fission because a large nucleus breaks into smaller nuclei the process must be fission because neutrons are formed