When it comes to electron configuration and orbitals, it's important to first identify what exactly we are trying to identify. Below is a given example:
Looking at the periodic table, identify the alkali metal family on the periodic table, or group one elements:
Notice how each configuration has an exponent of , representative of a single electron in their s-orbital.
The correct response would be 3. The alkaline earth metals would tend to lose its valence electrons, in this case 2 of them at different energy levels, to form the same respective ion, which is +2.