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.
Divide this amount into eight to 12 servings each day, feeding approximately two to three hours apart, from a bottle. After 4 weeks of age, wean your puppy onto solid canned or dry foods; moisten dry foods with low-sodium broth or formula for the first week or two of weaning.