Chemical modification of substances
If you start from the chemical name of substances, then mostly solids are meant. Like almost everything, these can also be changed by adding or extracting other substances.
If you familiarize yourself with the Natural sciences deal, you arrive neither at physics nor at chemistry past. Wherever there is a bang and smell, at least that is the student definition of this science, it is about the substances and their possible chemical changes. But what is that anyway?
What are chemical substances?
- Chemical substances are primarily solid substances that are either in their pure form as elements or as mixtures of substances.
- The most important substances are, for example, table salt, iron, water or ethanol (alcohol). Of course there are many more substances that are also divided into different substance groups.
- Every chemical substance has its own volume and thus has its own mass.
- Also the energy is clearly defined for each substance.
- However, you can find the individual connections in different forms. If you take iron as a material, you will find nails, wire, plates or completely different shapes, for example. Nevertheless, it remains iron with all its properties.
Consciously or unconsciously, you regularly take a chemical or physical ...
These changes in substances are possible
- You can subject substances to a change in a physical way. If you stick to iron as an example, you can bend, draw, cast, forge or process it in other ways. To do this, you always have to supply and use energy in some form to bring about the change.
- However, if you want to bring about a chemical change, you need an additional substance.
- Again, you can use iron as an example. If you leave iron unprotected under the addition of oxygen and water, i.e. simply exposed to the weather, it will start to rust. It breaks down to iron oxide, which you can see as brown, porous and flaking spots.
- But give an acid on iron, such as hydrochloric acid, you get a different chemical reaction and thus a completely different change in the substance iron.
You can also explain the chemical changes of substances on paper very simply, but clearly. If you change it mechanically, i.e. fold or crumple it, it remains dry paper. If you put another substance such as water, paint or oil on the paper, you also change the properties of the sheet - such as strength, flammability or mass.
