The bits of material that fall to Earth after an eruption are called tephra.

Here's a breakdown:

* Tephra: This is a general term for any solid material ejected from a volcano during an eruption. This can include:

* Ash: Fine, powdery material

* Lapilli: Pebble-sized fragments

* Blocks and bombs: Larger, often angular pieces of rock

Let me know if you'd like more information on tephra or volcanic eruptions!