Concerned is a synonym of Anxious. Anxious is the opposite of Calm. Calm is a synonym of Mild. 
Electricity is related to Force. Force is a synonym of Power. Power is related to Responsibility. Responsibility is related to Ought. 
Concerned <--Synonym--> Anxious <--Antonym--> Calm <--Synonym--> Mild 
Electricity <--RelatedTo--> Force <--Synonym--> Power <--RelatedTo--> Responsibility <--RelatedTo--> Ought 