You meet in everyday life water in different to form: frozen into ice, as a liquid or as a water vapor. Depending on temperature it takes one of these so-called Physical states a.
But what exactly is a state of aggregation and what does the whole thing look like in the particle model out?
state of matter definition
Just like water, other substances can exist in different states. For example, stone is also used at high temperatures and pressure liquid, for example inside the earth’s mantle. You then refer to this as magma or lava.
Although it continues to same stuff acts, it now has a different appearance and properties. He is in another physical state.
A physical state denotes the different forms and physical propertieswhich is a substance under certain Print- and temperature conditions owns. You also speak of manifestations, phases or states of matter.
The appearance of a substance is therefore related to its temperature together and the Print, which you exercise on him. But what exactly does increasing the temperature of a substance cause it to change its shape?
You can answer this question best with the so-called Particle model of matter respond.
State of matter particle model
A physical model is a simplified representation of reality. In it, complex physical phenomena are often reduced to their most important properties. Less important details are omitted in order to better work with the model.
Matter consists of atoms, which are made up of protons, neutrons and electrons. Protons and neutrons are in turn made up of quarks. However, in order to explain some phenomena, such as the states of aggregation, it is sufficient to refer to the interactions between atoms limit and ignore their building blocks.
That particle model is a simplified representation about the structure of matter. be there Atoms and molecules of a substance simplified reduced to small, monochromatic shapes (e.g. circles, triangles, squares). All atoms or molecules of the same substance have the same shape and color.
These particles interact (interact) with each other: they attract, repel and form bindings between each other. The strength of these bonds between the particles determines the shape and stability of a substance.
In the particle model you distinguish between homogeneous and heterogeneous fabrics. Homogeneous substances consist of one element, while heterogeneous substances are a mixture of two or more elements. Figure 1 shows you how you can represent this.
The specific properties of a substance result from these interactions between the particles emergence phenomenon. Temperature is an example of emergence.
Do you want them? temperature of a substance, you supply it with heat. warmth is a form of energy, which is partially absorbed by the particles of the substance. This increases their energy.
temperature is a measure of that average energy of the particles in a fabric. The greater the energy of the particles, the higher the temperature of the substance.
The particles in a substance all have slightly different energies, so you determine the mean value of these energies for the temperature.
The high energy of the particles comes largely from their kinetic energy (kinetic energy). The particles in a hot substance also have a high kinetic energy and therefore move faster.
You can find more information on this in the explanation of the kinetic theory of gases.
The mean kinetic energy (temperature) and the bonds determine how strong a substance is. The stronger the bonds and the lower the average kinetic energy, the stronger a substance.
States of Physics
In physics you distinguish many different states of matter. All these states of matter are due to the similar physical properties of different substances defined under certain temperature and pressure conditions.
The four fundamental states of matter are solid, liquid, gaseous and plasma.
You also encounter these in everyday life and most substances can assume any of these four states.
Other phases of matter are for example superfluids or Bose-Einstein condensates. These rare states of matter only occur under special circumstances and substances.
State of aggregation Solid
If you take some ice cream out of the freezer, you immediately notice different properties. First of all, unlike water, ice has a fixed shape. You can trace this back to the particle structure.
In a solid, the molecules are very tight packed. Due to the small distances between them can be particularly strong bonds develop. These give the fabric a firm structure and shape. Due to the high density, solids can be Not or very little compress (compress/compact).
This applies to most solids. Only water is an exception here, as it has a lower density in the solid state than in the liquid. You call this the density anomaly of water.
The following figure shows the structure of a solid in the particle model.
Another characteristic of ice cream is its low temperature, so the particles have one low energy.
Atoms and molecules have a fixed place in a solid. So they don’t move around freely, they just oscillate around their resting position. You can imagine this in the particle model a little like vibrating balls in a grid (Figure 2).
in the solid state of matter the particles are close together and exert strong forces of attraction on each other. Due to their low energy, they possess one fixed place and oscillate around their rest position. Solids have one specific shape and a specific volumethey are not at all or only with difficulty compressible.
Bonds of varying strength can form between the particles, for example hydrogen bonds, van der Waals forces or ionic bonds. You can read more about the individual connections in the explanations of the same name.
While solids maintain their volume under pressure, temperature can affect this. Many solids stretch under heat off and contract when cold.
When constructing bridges, so-called expansion joints are installed because the material (usually steel) expands at higher temperatures in summer and shrinks in winter. Without these expansion joints, bridges would be unstable as temperatures fluctuated.
Incidentally, ice is an exception and is not subject to thermal expansion. Ice begins to melt at higher temperatures without expanding first. You also call this the anomaly of the water.
In general, you distinguish between two types of solids: crystalline and amorphous solids.
solid species
Ice cream is one of them crystalline solids, as well as diamonds, salt, and various types of crystals and metals. form their particles regular lattice structures out. You can recognize this type of solid by its often geometric shape, which consists of either a large crystal (single crystal), e.g. B. diamond, or from a composition of many small crystals (polycrystals) exist, e.g. ice.
amorphous Solids form against it no regular lattice structures and therefore often own one lower density as crystalline solids. For example, glass is amorphous. This type of solid can be produced, for example, by rapid cooling, since the particles cannot arrange themselves regularly.
Due to the arrangement of their particles distinguish between two types of solids. crystalline form solids regular lattice structures out. In amorphous Solids, on the other hand, are particles disordered.
You can also see the difference between the two types in Figure 3. Depending on the arrangement of the particles and the strength of their connections, solids can differ Characteristics own.
solid properties
Solids are characterized by having a fixed volume, even when subjected to strong forces. However, they can change shape under pressure. For example, if you apply some pressure to an ice cube, it will break into several small pieces. Such substances break under pressureyou designate as brittle.
On the other hand, if a substance deforms under tensile stressyou call him ductile. The particles in ductile solids can rearrange themselves to a certain degree, so that the substance holds together. However, you cannot pull these materials apart like chewing gum forever, from a certain tension even ductile materials break.
Physical state Liquid
If you now put the ice cube in a pot and turn on the stove, you can watch how it slowly turns into a liquid form – water. By supplying Thermal energy loosen the bindings and the particles can move more freely and quickly. You can see the particle model of water in the liquid state in the following figure.
The distances between the particles in a liquid are larger than in a solid. However, they are still held together by bonds, which is why liquids only compress little to let. Unlike solids, liquids can change shape and adapt to their container.
Liquids own a certain volume, fit herself in her shape however their container on. the attractions are between the particles lower than in solids, causing ye distance larger is and they can move more freely. The higher the energy of the particles, the faster their movements.
An important property of liquids is their viscosity. Viscosity describes how viscous a substance is. For example, water has a lower viscosity than honey.
How viscous a substance is depends on the strength of the bonds between its particles. The stronger these bonds in a liquid, the more viscous it is. Viscosity also depends on how fast a liquid moves flows and in their form a container adjusts.
Physical state Gaseous
If you continue to heat the water, it will start to boil at around 100 °C and eventually stop evaporate. Due to the high amount of energy supplied, the particles in a gas have a high speed and become Not more held together by bonds.
Due to the free movement of the particles gases fill the entire available space out.
The particles in a gas have large distances between each other, making gases themselves compress slightly to let. Gases therefore have neither a fixed shape nor a fixed volume.
in the gaseous state of aggregation the particles move because of their high energy very fast, they are far apart from each other and own no (or only very weak) ties among themselves. Therefore, gases fill all available space and are compressible. They have neither…