We cut apple slices and put one each in ziplock bags. Then we added 1 ingredient per bag: salt, lemon juice, vinegar, sugar, and oil. And we observed.
After 5 days, my kids felt the apples in the bags for firmness as well as looked at the apple’s color. They determined that lemon juice worked best!
The real-life application says that apples turn brown because of a chemical reaction between air and the fruit. It also asks kids to take a trip to the grocery store, look at the ingredients in bags of sliced apples, and figure out how those apples aren’t brown.
Original article and pictures take http://imaginationsoup.net/2015/10/why-i-like-the-curious-kids-science-book/ site