What is the significance of chemical reactions

Many enzymes special biological catalysts work in this way. Many industrial chemical processes rely on such catalysts. Up there, the chemical ozone with molecules containing three oxygen atoms helps protect the Earth from harmful UV radiation.

But also up there is chlorine, which gets into the atmosphere from chemicals chlorofluorocarbons, CFCs used in some refrigerators, air conditioners and aerosol cans. Chlorine is a catalyst, which steals an oxygen atom from ozone O 3 leaving stable oxygen O 2. At the same time, it forms an unstable intermediate chlorine-oxygen compound, which breaks down to release its oxygen. This leaves the chlorine free to repeat the process. One chlorine atom can destroy about a million ozone molecules every second.

In this video, Teaching students how to learn , Dave Corner explains how he uses Hub resources to teach about catalysts. Watch a demonstration of how platinum acts as a catalyst with an explanation of the use of platinum in catalytic converters in this video from the BBC.

Add to collection. Activity idea In this video, Teaching students how to learn , Dave Corner explains how he uses Hub resources to teach about catalysts. All materials are made of chemicals. Chemical reactions involve interaction between chemicals such that all reactants are changed into new materials. The properties of the new materials are different from those of the reactants. This is distinct from other changes such as evaporation, melting, boiling, freezing and mixing where changes involve no new substances.

While heat is often necessary to start reactions, this need not be the case. Chemical reactions involve breaking chemical bonds between reactant molecules particles and forming new bonds between atoms in product particles molecules.

The number of atoms before and after the chemical change is the same but the number of molecules will change. Although many chemical reactions proceed quickly, small, slow changes such as rusting or biological processes can take place over much longer periods of time.

Chemical reactions are reversible a fact often omitted in many science texts but in practice most differ from other changes children observe, such as melting, by being very difficult to reverse. Humans use chemical reactions to produce a wide range of useful materials; the breakdown of waste materials also involves chemical reactions that occur naturally in the environment. For some human made wastes, there are no such reactions and they cause problems as a result.

In teaching about chemical reactions at this level the emphasis should be on improving student understanding of the importance of chemical reactions in our lives in producing many of the things we take for granted as well as improving their recognition and understanding of what is involved in a chemical change. It is not necessary at this stage to talk about particles such as atoms or molecules or chemical bonds.

In learning about chemical reactions students will need to describe various substances, which at this level will be materials they are familiar with the kitchen and changes involving cooking are very good starting points.

They will need to be able to identify changes in these substances with the purpose of eventually recognising when new chemicals have been produced i. As mentioned above, this is can be difficult as students often fail to see the difference between an egg white going through a change from liquid to solid as it is cooked and changes such as melting chocolate or boiling water which do not involve chemical change.

Teaching will need to be focused on what happens when new substances are formed. These ideas are also explored in the focus idea Problems with classifying. Environmental effects of chemical reactions can also be considered, for example how we dispose of some chemicals once they are produced, in forms such as plastic bags.

At this stage it is important that students are encouraged to put up their ideas and discuss them in small groups. All alternatives should be considered with no resolution at this stage. Chemical reactions are the most important types of events in the universe. It's through chemical reactions that plants grow, produce fruit, and become compost for new plants.

It's because of chemical reactions that human beings and all other animals reproduce, digest, grow, heal, and think. But what exactly are chemical reactions? Why are they so important? Elements are the basic substances that make up matter in the universe.

Each element is a chemical. Elements that form bonds are called molecules. An oxygen molecule, for example, has two oxygen atoms. Chemical reactions occur when molecules interact and change. Bonds between atoms in molecules break and are reformed in new ways.

Chemical reactions are at the heart of literally every biological process in the universe. Stars form because of chemical reactions; our sun ignited because of chemical reactions in its core.

Life developed on Earth as a result of chemical reactions. The "circle of life" is, at its heart, a series of chemical reactions. Even our ability to think and move is a result of chemical reactions that occur in our bodies.

Chemical reactions are the reason we exist on the Earth, and, of course, they are the reason we are able to ask questions.