Who was the first to state the concept of an atom? neils bohr john dalton ernest rutherford democritus

Iam in desperate need of with this !

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

Which best explains why an iceberg floats?