Chemical reactions and catalysts. A chemical reaction involves a chemical change, which happens when two or more particles (which can be molecules, atoms or ions) interact. For example, when iron and oxygen react, they change to a new substance, iron oxide (rust).
It's important for parents to start weaning babies from bottles around the end of the first year and start getting them comfortable drinking from cups. The longer parents wait to start the transition, the more attached kids become to their bottles and the more difficult it can be to break the bottle habit.
How to Wean a Baby. Tips to make weaning from breast and bottle easier for you and baby. Turn to this quick give-it-up guide to help you break Baby's dependencies on Binkys, bottles, blankies, and the breast. The first step in weaning your baby is getting him used to a cup.