How to shoot a crossbow and throw bombs? (The Witcher 3: Wild Hunt)

I want to ask a few questions because I can't figure it out.

1. If you put an elixir in a cell in your inventory, it is displayed on the screen. And if you put a bomb in a cell, there is nothing on the screen. Is that how it should be?
2. Both bombs and crossbow are locked on one button (SCM). How to switch them?