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.
In general, it is advisable to start weaning your baby off breast milk once he/she reaches between 4 to 6 months of age. Babies born pre-term should be fed breast milk until they are 6 months old. Your babyâs digestive system may often give you some clues about when heâs ready to start off with some solid foods.