How is a mixture the same as a compound and how is it different

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

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

What substance has a mass of 9.5g and volume of 2.1cm^3