Do you like eating chips?When you open a bag of chips, you may find that it's far from full. Some believe it is because companies are trying to fool the customers and increase the money the year. However, there are reasons why there is extra(额外的)air in the bag.
The empty space helps protect the chips during its journey from the production factory to the store and then your home. This makes sure that customers get as many full chips as possible and not a bag of crumbs(碎屑).
What's more, it's actually not oxygen inside the chip bag. It's pure nitrogen(氮气) . Companies choose nitrogen to fill their snack bags because the gas doesn't react(起化学反应) with anything else, while the oxygen will react with the oil in the chips and cause them to go rancid quickly. This is why unopened bags of chips are still fresh two to three months later, thanks to nitrogen. ，But don't worry, you're not paying for the nitrogen. Chips are sold by weight. If you look at the weight on the bag and you can get yourself a scale and weigh it, you'll see that the chips weigh exactly what it says on the bag.
