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.
Time it right. Wean your baby from a pacifier after 6 months old, when the risk of SIDS drops and ear infections become more likely. If you want to help him give it up slowly, try to limit it to nap time or sleep only, Sexton says. Also, try not to wean when other life changes occur.