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.
Beginning the Process. 1  1. Start slowly. Begin the weaning process in a gradual, slow manner. 2  2. Watch your baby for signs of weaning. Your baby will most likely let you know when he or she is ready to wean, such as an interest in solid food and a loss of interest in nursing. 3  3. Introduce food.