What must happen before any work may be performed in a confined space?

Well you need it to be clean, 2 you need space where it is, 3 you need to prepare for what you are about to do,

where the right clothes and gear,tools, anything you need for it.

4th make sure you can concentrate on what you need to do and that there is no distractions, 5th make sure your ready and not stressed,

6th get help if you need a tutor etc

also i will update if i have anything else to say

A. they hold atoms  together with a molecule.its a force that exist between molecules. hope this .