Question

Why are both lithium and cesium alkali metals, when lithium has three electrons

and cesium has 55

Answer 1

Because they both have one electron in their outermost shell

Step-by-step explanation:

Both lithium and cesium are classified as alkali metals because they both have just one electron in their outermost shell.

The electronic configuration of both atoms are:

Lithium = 2, 1

Cesium = 2, 8, 18, 18, 8, 1

Now we can see that the outer shell of both elements have just one electrons.

Division into groups is based on the number of outer most shell of each element