iPad Air - Apple pencil gen 1

No. While the Pencil is charging, it cannot be used.

However, just plugging the Pencil into your iPad Lightning port will rapidly charge the Pencil’s tiny battery. A few seconds charging will provide 15 minutes even if the battery is very low, the Pencil will fully recharge in 10-20 minutes.

Be aware that charging from the Power Adapter charges the Pencil more slowly - typically several hours.

It makes no difference whether you use the iPhone or iPad Power Adapter (charger) to charge the Apple Pencil. The Pencil will charge slowly with either - but will not be usable with the iPad whilst connected to the charger.

The fastest method of charging the Pencil is to connect directly to the Lightning port of the iPad.

when The Apple Pencil is charging the pencil appears to turn off not allowing you to use it at the same time. sadly, no.

the iPhone and iPad lightning cable is the same lightning cable apple has used for a while. any lightning supported device can use the same cable.