# Question #05cb7

Jul 7, 2016

$\text{Cs}$

#### Explanation:

Cesium is an element located in period 6, group 1 of the periodic table and has $\text{Cs}$ as its chemical symbol.

Cesium is so reactive that it must be handled under inert gases. Moreover, the metal is usually kept in vacuum-sealed ampoules made from borosilicate glass.