The Characteristic properties of matter Are chemical or physical properties that can help identify or distinguish one substance from another. Physical properties are characteristics of a substance that are observed with the senses. Chemical properties are characteristics that describe how a substance changes from one substance to another during a chemical reaction.
Some physical properties of a substance are density, solubility, melting point, color and mass. The chemical properties of the material include flammability, reactivity with acids and corrosion. Some examples of how the properties of matter can help identify an element is to compare densities of different elements.
An element such as gold has a density of 19.3 grams per cubic centimeter while the density of sulfur is 1.96 grams per cubic centimeter. Similarly, the melting points of substances such as water and isopropyl alcohol are different.
Physical properties of matter
The physical properties of matter are properties that can be measured or observed without changing the chemical nature of the substance. Some examples of physical properties are:
- Density: quantity of matter that has an object, is calculated by dividing the mass by volume.
- Magnetism: the force of attraction between a magnet and a magnetic object.
- Solubility: measure of how well a substance can dissolve in another substance.
- Melting point: The temperature at which a substance changes from solid to liquid.
- Boiling point: The temperature at which a substance changes from liquid to gas.
- Electrical conductivity: is a measure of how well electrical currents move through a substance.
- Thermal conductivity: is the rate at which a substance transfers heat.
- Malleability: is the ability of a substance to be rolled or milled in various forms.
- Brightness or luster: is how easily the object reflects the light.
Chemical Properties of Matter
Chemical properties describe the ability of a substance to transform into a new substance with different properties. Here are several examples of chemical properties:
- Combustion heat: is the energy released when a compound undergoes complete combustion with oxygen.
- Chemical stability: refers to whether a compound will react with water or air (chemically stable substances will not react).
- Flammability: A compound's ability to burn when exposed to a flame.
- Reactivity: ability to interact with another substance and form one or more new substances.
Physical states of matter
Matter is anything that occupies a space, which has mass and can be perceived by our senses. The material can be classified according to its physical state: solid, liquid and gaseous.
1- Solids and their characteristic properties
All solids have mass, occupy a space, have a defined volume and shape, do not slide through space and can not be compressed or have a rigid shape. As examples we have: wood, books, sponges, metal, stones, etc.
In solids, small particles of matter are close together and touch each other. The particles are so close together that they can not move very much with very little space between them.
2- Liquids and their characteristic properties
All liquids have mass, occupy a space, have a defined volume but not a definite shape (as they adapt to the container where they are), can be compressed to a very small degree and can slide through space. Examples are: water, kerosene, oil, etc.
In liquids, small particles of matter are a little further from each other, there is more space between them (compared to solids) and they do not touch each other. Therefore, particles can move between spaces, pushing and colliding with other particles, constantly changing direction.
3- Gases and their characteristic properties
All gases have mass, occupy a space, have no definite volume or shape, can be compressed to a large extent and can diffuse into space. Examples are: hydrogen, oxygen, nitrogen, carbon dioxide, steam, etc.
In gases, small particles of matter are much farther apart, there is much more space between them (compared to liquids) and they do not touch each other. The particles have maximum freedom of movement so they push and hit other particles constantly changing direction.
Changes in the state of matter
Matter can be converted from solid state to liquid state and vice versa, and from liquid to gaseous state and vice versa. This conversion is called the change of state of matter and occurs by changes in temperature:
Fusion
Changing the state of matter from solid to liquid by increasing the temperature. When a solid substance is heated, the heat causes the particles to vibrate more vigorously.
Upon reaching the melting point the solid particles have sufficient kinetic energy to overcome the forceful forces of attraction that hold them in fixed positions, and they break to form small groups of liquid particles.
Boiling or vaporization
Changing the state of matter from liquid to gaseous by increasing the temperature. When a liquid substance is heated, the heat causes the particles to move even faster.
Upon reaching the boiling point the liquid particles have sufficient kinetic energy to overcome the pulling forces that hold them in fixed positions, and separate into individual gaseous particles.
Freezing or solidification
Change of state of matter from liquid to solid by means of the decrease in temperature. When a liquid substance is cooled, its particles lose a lot of kinetic energy. Upon reaching the freezing point the particles stop moving and vibrate in a fixed position becoming solid particles.
Liquefaction or condensation
Change in the state of matter from gaseous to liquid by means of a decrease in temperature. When a gaseous substance is cooled, its particles lose a lot of kinetic energy which causes them to attract each other to become liquid particles.
Sublimation
Some materials change directly from their solid state to their gaseous state or vice versa, without going through the liquid state. When these solid substances are heated, their particles move so fast that they separate completely forming vapor or gas, and vice versa when the process occurs from gaseous substance to solid.
References
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