Tim Cook answered
The lewis structure of Cu(NO3)2, also known as copper (II) nitrate, is given below:
As an oxidant, care should be taken around copper (II) nature as it is an irritant to the eyes and skin. The compound is available in bulk from most commercial chemical providers at around $158 for 2.5kg.
Copper (II) nitrate is also useful in the lab, as this YouTube user demonstrates: