Even in the lower grades at school, children are told what substances are, give simple examples and explain what substances are.
The definition of word "substance"
Simply put, a substance can be called all that of which any body consists. In the older classes, matter is called matter, of which the physical body consists, and it has certain physical and chemical properties. A substance is also called a collection of atoms or molecules that are in a certain aggregate state. All substances make up a certain body. Basically, we intersect with its solid state, in which particles can hold their shape and not spread. But it may contain liquid and gaseous substances. That is, what are the substances and bodies in terms of origin? Bodies can be created by nature and through human intervention.
The usual stone that rolls in the mountains was created by nature, and the mineral grown in the laboratory, inserted into the frame, is already the work of man, an artificial body. But all the substances that are simple (more on this later) are created by nature. Different mixtures of them could already be created by people, but it was she who laid the main basis. Answering the question, what are the substances and bodies, we can say that they are divided into natural and artificially created.
Types of substances by the interaction of particles, or by the state of aggregation
The substance is divided into several groups according to different characteristics. So, we can characterize what substances are depending on the interaction of particles. Strong particle interaction is characteristic of solids. Gases are characterized by an almost absolute absence of interaction. Liquid substances are located in the middle between solid and gaseous materials - particles interact, but not as much as in solids. This property is explained by the fact that there are gaps between the particles that make up the material, and in solid materials these gaps are very small, and in gaseous ones they are huge. Substances are divided into the same groups by the kinetic energy present in the particles and the potential interaction energy. In liquids, these energies are practically comparable. In solids, potential energy predominates , in gases, on the contrary, kinetic. The answer to the question, what are the substances in nature, can be any of these options. Any of the above conditions or characteristics are found both in objects created by nature and in things that have arisen as a result of human activity.
Interestingly, one substance can be in different states. So, the simplest example is water. At low temperatures, the liquid turns into ice, into a solid. When the temperature rises to 100 degrees Celsius and above, water from a liquid turns into gas.
Chemical separation
In chemistry, it is customary to distribute substances into two main categories - these are individual substances and mixtures. That is, what are the substances in chemistry? Pure previously, and now individual substances are called those that can not be divided into simpler parts, they are indivisible. Mixtures are materials having several components in their composition. In fact, it turns out that the mixture may consist of several individual substances.
An individual substance, in turn, can be simple or complex. Simple - this is a substance that consists of atoms of only one chemical element, complex - of several: two or more. Simple is also called elemental, and complex substance is called a compound.
As mentioned earlier, the mixture consists of several pure substances, and in this regard they are divided into homogeneous and heterogeneous, or solutions and mechanical mixtures. A simple example of what kind of a solution can be is ordinary tea. It consists of two or three components - water, tea leaves and sugar. Sugar is uniformly placed on water and cannot be detected, except for taste.
But if you pour a lot of sugar into tea, and it does not dissolve completely, then it will already be a mechanical mixture. Part of the sugar will dissolve, and part will lie at the bottom. Because of this, the samples of tea in the upper layers will be slightly different, at the bottom it will be sweeter, and at the top - less. The mixture will also be an elementary mixture of sand and sugar. The particles will be mixed, it will be difficult to separate them, but they will remain at their properties, and will not create new compounds.
Organic and inorganic substances
To the question, what are the substances in nature, we can answer: organic and inorganic. Inorganic is any substance that can be formed without the participation of a living organism and constitutes inanimate nature. Organic matter is diametrically opposite - it is formed only with the participation of a living organism and is part of this very living organism. An example of an inorganic substance, again, is the well-known, accessible, and so necessary for life water, also air, namely oxygen, various mineral salts. Organic substances include fats, carbohydrates, pigments, proteins. It is funny that a section on this type was made from the opinion of scientists about living things as special organic compounds, and all other objects of inanimate nature were classified as inorganic. As it turned out later, in the human body there are a lot of inorganic substances, as, indeed, in the body of any animal on our planet.
A distinctive feature of organic substances can be considered that almost all of them have carbon. Most inorganic substances have a high melting and boiling point, organic - on the contrary.
Fire classification
It is interesting that the fireman will most likely answer the question of what substances and materials are - combustible and non-combustible. Between them there are still flammable substances that can catch fire if there is a constant exposure to the flame, but if you remove the source, it will go out. Accordingly, a combustible substance or material is able to burn when exposed to a source, and can even self-ignite. Non-combustible substance is not able to burn in the air. All children will learn more about this at the lessons of labor protection or life safety.
Effects on the human body
All substances found in nature can be divided into hazardous and safe. Those that have already been mentioned above can be classified as dangerous - burning. What is the danger? They can harm the health of a person who will be in the focus of fire. It will be a physical effect on the skin: burns or effects on internal organs through the respiratory tract. By the way, in the same way, a negative effect occurs during smoking. Smoking is not only tobacco products, which contain many known harmful substances to the human body, but also narcotic drugs.
What are the narcotic substances
Not all drugs are taken through smoking; some are injected into a vein, inhaled as a powder through the nose, or eaten as a pill. But all of them have side effects, despite the fact that before that they could bring a feeling of joy and happiness, high spirits or some other positive effect. All these effects are short-lived, but everyone knows that the harm from them will definitely last much longer.
conclusions
If you ask a child: “Tell me what substances and materials are, give examples,” then he will have many different answers. It is important to make clear to the student that the same substance can belong to several species, which were listed above, differ in certain characteristics. From a very young age, knowledge of what substances are, will expand with the study of school sciences.