Now I am going to carry out 1 test. I am going to burn magnesium in air to form magnesium oxide.
Description before
Magnesium is an element which is a shiny metal as well. It’s solid and feels heavy for their size. I can’t see air (oxygen) because it’s gas at room temperature. Here is a diagram of magnesium and oxygen-
During the reaction
Magnesium burns very brightly when heated in air.
Some metals are very reactive. They easily take part in chemical reactions to make new substances.
Magnesium is like this. It is heated in a Bunsen burner; it ignites and burns with a brilliant white flame. By the action of fire, the magnesium reacts with the oxygen in the air and form magnesium oxide.
Description after
When two elements react together to form a compound, the compound is different to either of the two elements both of appearance and in physical properties. So the magnesium has gone grey powder. The oxygen reacted with magnesium and made it very light and dull.
All substances have mass and therefore must be composed of atoms. These atoms and how they assemble themselves in the substance determines their chemical and physical properties. Substances can be classified according to how these atoms are assembled and are known as Classification of Matter: All matter falls into one of three categories: elements, compounds or mixtures. Furthermore, mixtures can be classified as homogeneous or inhomogeneous. The scheme looks something like the diagram below:
This classification depends upon how we try and separate matter into its basic components. This separation is called the "process". There are two processes: a physical and a chemical process.
If we have a sample of matter and can find a physical process such as evaporation, magnets, colour etc. to separate it then the sample is a "mixture". Furthermore if the sample is a mixture of solids and liquids (e.g., sand and water) etc. or two or more liquids that don't mix (e.g., oil and vinegar) then the mixture is "inhomogeneous". Otherwise the sample is a "homogeneous" mixture.
If there is no physical process that will separate the sample then the sample is a "pure" substance. If a chemical process such as combustion or oxidation breaks the substance down to its constituent atoms then the substance is a "compound"(e.g., salt, sugar, water). Otherwise the substance is an "element" (e.g., copper penny, aluminium foil). Compounds are made up of molecules or salts. Elements are made up of single types of atoms.
There are 9 types of energy. They are kinetic; heat, light, gravitational potential, chemical, sound, electrical, nuclear and elastic potential energy. Energy can’t be created or destroyed. It can only transform to another form. In magnesium there was stored energy which is chemical energy. When it’s got heat it produced a white flame so chemical energy turned into light energy. When it’s got burn and the magnesium turned into grey powder the light energy transform into thermal (heat) energy.
In a chemical reaction there is always the same number of particle before and after a reaction. Therefore, there is the same mass. This is called the conversation of mass. The particle in a chemical reaction doesn’t destroy or increase; it’s just rearrange to form a new substance.
