Chemical Reactivity And Anomalous Properties

Anomalous Second Period Elements

The first element of groups 1, 2, and 13–17 (like Li, Be, and B to F) often behaves differently from the rest of its group. Why? It comes down to small atomic size, a large charge/radius ratio, and high electronegativity.

Trends in Chemical Reactivity

If the periodic table were a city, the most action would happen in the outer suburbs. Chemical reactivity is highest at the two extremes of a period (excluding noble gases) and lowest in the center.

Problem. Show by a chemical reaction with water that $Na_2O$ is a basic oxide and $Cl_2O_7$ is an acidic oxide.