Will Pokemon Black and White be for the 3DS?

No, Pokemon Black and White were released for the Nintendo DS console, not the 3DS.

The 3DS games in the Pokemon series are:

* Pokemon X and Y

* Pokemon Omega Ruby and Alpha Sapphire

* Pokemon Sun and Moon

* Pokemon Ultra Sun and Ultra Moon

* Pokemon Let's Go Pikachu and Let's Go Eevee

* Pokemon Sword and Shield

* Pokemon Brilliant Diamond and Shining Pearl

* Pokemon Legends: Arceus

* Pokemon Scarlet and Violet