6. - General propirties: They are those that all matter shares and allows us to recognice matter. These are general properties:
7. - Mass: it is the quanty of matter that a body has
8. - volume: it is the space that occupies this matter.
10. MEASURE OF MATTER: Magnitude : It is any property of matter that you can measure, for example: the weight, the length, the speed, etc. To measure : It is to compare a magnitude with the unit, for example: 3 kg., 2 m., 50 km/h, etc. International System of Units (S.I.): Almost all the countries of the world have adopted this system of units, so that almost everybody measures in the same way.
11. In the following chart we can see the most important units: INTERNATIONAL SYSTEM OF UNITS (S.I.) Magnitudes most important Length Mass Time Temperature
15. THE DENSITY: Density: It is the relationship between the mass of a body and the volume that it occupies. Mathematically it is expressed this way. The most important unit to measure the density
16. is the g / cm 3 , it is also used kg / m 3 . Mass : it is the quantity of matter that a body has. The mass doesn't vary from one place to another; a body has the same mass on the Earth or the Moon. The most important unit is the kg. Weight : It is the force with which the Earth attracts a body. The weight varies from one
17. Weight : It is the force with which the Earth attracts a body. The weight varies from one place to another; one body doesn't have the same weight on the Earth or on the Moon. We will study the units later. Volume : It is the space that a body occupies, or how big or small that it is, the most important unit is the m 3 , although the smallest bodies are measured in cm 3 .
18. MATERIALS: The objects are manufactured with multiple materials. Each material is selected carefully for the function of its properties. The growing industrialization demands that we look for new materials to manufacture novel objects or to improve old materials. Our scientific knowledge also allows us to manufacture substances that have never existed. For example recently they have invented: