Certain Period 2 Elements Exhibit Behaviors Similar to Period 3

Multiple Choice

Certain Period 2 elements exhibit behaviors similar to Period 3 elements immediately below and to the right. One of these interesting diagonal relationships occurs between beryllium and aluminum. Which of the following is one of their differences?

A) Some aluminum compounds and all beryllium compounds show significant covalent character in the gas phase.
B) Beryllium forms bridge bonds in its hydrides while aluminum does not.
C) Both form oxides that are impervious to reaction with water.
D) The cations for both strongly polarize nearby electron clouds.
E) Beryllium occurs in nature as the uncombined element, whereas aluminum does not.