Mental is related to Mind. Mind is related to Thought. Thought is related to Memory. Memory is related to Part. 
Nuclear is related to Energy. Energy is related to Quality. Quality is related to Skilled. 
Mental <--RelatedTo--> Mind <--RelatedTo--> Thought <--RelatedTo--> Memory <--RelatedTo--> Part 
Nuclear <--RelatedTo--> Energy <--RelatedTo--> Quality <--RelatedTo--> Skilled 