Final answer:
Russia is the largest nation-state in terms of territory size.
Step-by-step explanation:
The largest nation-state in terms of territory size is Russia. With a landmass of over 17 million square kilometers, Russia is the largest country in the world by area. It spans two continents (Europe and Asia) and has diverse geographical features, including the expansive Siberian region and the Ural Mountains.
Learn more about Nation-state territory size