1. first nuclear reactor

atomic mass

2.

fusion

3. decaying nuclei

curie

4. number of neutrons and protons

Becquerel

5. builds heavier elements

Fermi

6. discovered radioactivity

fission

7. unit of radiation

neutron

The correct matches are as follows:

1. first nuclear reactor

Fermi - an italian physicist who made the first nuclear reactor

2. 1/0 η

atomic mass

3. decaying nuclei

fission - nuclear reaction from a heavy elements to lighter elements

4. number of neutrons and protons

neutron

5. builds heavier elements

fusion - nuclear reaction from two or more elements to a heavier element

6. discovered radioactivity

Curie

7. unit of radiation

Becquerel