Which river forms much of the border between the United States and Mexico?

Dmitri Mendeleev organized the periodic table in 1869, predicting properties of undiscovered elements.

Aristotle tutored Alexander, influencing his leadership and spreading Greek philosophy across conquered regions of the ancient world.

Ozone’s formula is O3, consisting of three oxygen atoms, playing a vital role in absorbing harmful UV radiation in Earth’s stratosphere.

The Peace of Westphalia (1648) concluded the Thirty Years' War and established principles of sovereign states and non-intervention.

The Rio Grande (Río Bravo) forms a long stretch of the US–Mexico border, serving as a geographic and political boundary.