KS3 Chemistry - Recycling

In this video we're going to learn about Earth's resources and recycling. So we'll cover the Earth's resources including renewable and limited resources and then also take a look at how recycling can maximize the use of our limited resources. Now the Earth's resources can be split into two main categories. Renewable resources and limited or non-renewable resources. Renewable resources are the ones that can be replenished. If we consider the example of trees, these may be cut down to produce paper or wood for buildings but they can be replanted to continue to produce these resources again and again as long as they're given enough time to regrow before being chopped down again. On the other hand, limited resources can't be replenished within our lifetime so they will eventually run out. They are sometimes described as finite which is the opposite of infinite and means they won't last forever. Some examples include metal ores and fossil fuels both of which take a very long time to produce. Now let's take a closer look at these limited resources starting with metal ores. These are mined out of rocks in the Earth's crust and then the metal is extracted from the ore and processed. We can use this processed metal for things like making coins, buildings and electronics. If we keep digging deeper and deeper to extract more metal ores though eventually they will all run out. Fossil fuels meanwhile are a group of substances including coal, crude oil and natural gas and these are basically just the solid, liquid and gaseous forms of fossil fuels. Importantly though they're all formed in the same way from dead plants and animals they get buried for millions of years. Luckily for us we can then extract and process them and then use them for stuff as well. For example we can burn them to release energy for things like lighting, transport and heating or we can turn them into plastics which we can then use to make everything from carrier bags to building products to clothing. The key point to remember though is that fossil fuels take a really long time to form and so we can't make any more of them. If we keep using them up the way that we are currently they will eventually run out. Also it's worth noting that burning fossil fuels releases lots of dangerous chemicals into the atmosphere as well. Next let's explore how recycling can maximize the use of limited resources. There are actually three R's we need to think about when we want to make the most of earth's valuable resources. Reduce, reuse and recycle. The first R, reduce, means we want to cut down how many products we use that come from limited sources. For instance instead of leaving the lights on when you leave a room you could switch them off so you don't use as much energy. The next R, reuse, means trying to get as much use as possible out of an item that is produced from a limited source. As an example here the next time you think about buying a plastic bag to carry your shopping in try to get a more durable reusable bag that you can bring with you on your next trip so you don't need to buy a new one each time. The last R then, recycle, means we use old items that we don't want anymore to make new products that we can use again. For instance when you finish the drink from an aluminium can don't throw the can away in a normal bin but instead throw it in a recycling bin. This means it'll be taken off to a recycling plant where it can be repurposed into new metal items like aluminium foil or even a brand new can. Now there are loads of good reasons to recycle including saving limited resources, using less energy, saving money and producing less waste. And to help you understand each of these let's take a look at how they apply to recycling aluminium cans. One big reason why recycling is so great is that it saves limited resources on the earth like the metal ores we find on the ground. If we didn't recycle the aluminium in cans we'd need to extract more aluminium ore from rocks by mining and this would use up limited resources. When we recycle though we don't have to dig up as many new metal ores and other materials because we can just reuse the old ones instead. Recycling also uses less energy than making new products from scratch does. So if you remember that a lot of our energy comes from burning fossil fuels by recycling we save energy and this in turn saves fossil fuels making these limited resources last longer. Recycling also tends to be cheaper than making brand new products. The processes of mining, transporting and extracting the aluminium all use lots of energy and that energy is expensive. A lot less energy is needed to recycle something than to make it from raw materials so this has the effect of making it cost a lot less. And then a final way that recycling is so useful is that it produces less waste because the materials like aluminium are used again and again instead of being thrown away. This means recycling stops useful aluminium from ending up in rubbish dumps. This is a good thing because rubbish dumps take up a lot of space and can sometimes even pollute the earth and water around them as well. If you haven't heard yet you can find all of our videos on our website cognito.org You'll also find questions, flashcards, exam style questions and passpapers and we track all of your progress so that you always know what to study next. So sign up for free by clicking here or browse our playlist here on YouTube.