In Science, we have been learning about reversible and irreversible changes. We found out that some materials act as reactants and when something is done to them they change. Some changes are reversible, but others are not and we call this irreversible. Our first task was to decide, when looking at a list of changes, what was reversible and what was irreversible.
Next, we conducted two tests with some materials. First we added white vinegar to milk. A chemical reaction occurred and it caused the liquid to separate from the mild solids. It created a new material called Casein plastic. It was used from 1900 until 1945 to make some plastic products likes buttons and combs.
In the second test, we added biacarbonate of soda to vinegar in an old water bottle and put a balloon on top. The vinegar fizzed up and the balloon inflated. A chemical reaction was occurring and it was creating carbon dioxide. We found out that carbon dioxide is used to make drinks fizzy and can also be used in fire extinguishers.
