Combustion, Respiration and Photosynthesis

Combustion is when we burn a fuel, it is a chemical reaction and an exothermic one (these reactions are those who give out heat). For combustion, we need hydrocarbon (which is combustion's fuel) and oxygen, the oxygen burns the fuel and leaves us with carbon dioxide, water and energy!!

Combustion's word equation is:

As for respiration, it is a type of combustion. Our cells get energy: glucose ( glucose is the fuel) to be able to live, this process is called respiration.

Respitation's word equation is:

Photosynthesis is how plants get their "food" (energy) to keep on living, the substances it needs and gives away are th same as those in respiration, except they are inverted:

Elements, Mixtures and Compounds

Elements

Elements are substances which cannot be broken down into anything else, because they only have 1 type of atom. Elements are those which can be found in the periodic table:

The Rows are called periods and the columns are called groups; in group 1 are found very reactive metals, in group 8 are found those gasses which are very unreactive.

Mixtures

Mixtures are easy to separate, this is because in a mixture there really is no new substance made, in other words the substances are not bonded together, be it elements and/or compounds. You can use distillation, filtration, evaporating, magnetism or chromatography to separate them.

Compounds

These are very difficult and sometimes impossible to separate because of their fixed composition of 2 or more elements chemically bonded together. When a compound is created, a chemical reaction occurs, you can tell this is happening because you can see a light, the smell that is given out, the change in temperature, the colour changes, there are bubbles (a gas is given out) and/or a new substance is made.