Matter, Mixtures, and Material Properties Explained
Basic Concepts of Matter
Atom: Basic parts which consist of matter (protons, neutrons).
Molecule: Clusters of atoms that are in some substances (H2O).
Chemical element: Pure substances found in nature consist of countless atoms (gold, copper).
Compound: Substance formed by two or more elements with a constant rate and specific (H2O, CO2).
Pure substance: Elements with novel composition or properties (sugar, iron).
Mixtures and Separation Techniques
Mixture: Substances formed by several elements or compounds in varying proportions (its components are substances that form chocolate milk).
Heterogeneous: Mixtures that can distinguish at a glance which consists of several components (soup).
Homogeneous: Blends with many components that apparently cannot distinguish (chocolate, wine).
Separation Methods
Filtration: Used to separate components of heterogeneous mixtures of solids and liquids. In making the transfer to a filter, the solid cannot cross it and it is placed. The filter can be more or less so depending on the size of the particles of the solid.
Decanting: Is used to separate two liquids that are mixed (water and oil). The container that contains sinclina and was pouring. First, the liquid is suddenly up (it’s less dense).
Centrifugation: The mixing is done at high speed in a centrifuge; this way the solid particles move towards the bottom of the container and form sediment.
Magnetic separation: Method for separating mixtures with a component or a component of iron or iron dhacer, which is attracted to a magnet. Shi and extends the mixture passes over limant that natreurà and collect the metal.
Distillation: Separates the components of a liquid solution with different boiling points. When sescalfa mixture will boil and vaporize the substance is first that has the lowest point debullició. The vapor is collected in a condenser that, cool them back into the liquid.
Materials and Their Properties
What are the materials? The substances used to construct objects usually called materials (make, cement, nylon).
Natural materials are found in nature. Or raw materials are wood, wool, silk, cotton, oil, coal.
Artificial materials that are man made from the natural (paper, glass, plastic, steel, ceramics).
Material Properties
Hardness: Ability of a material that has not been scratched by another. Gypsum is soft to scratch with the nail, which is harder.
Elasticity: Ability of a material to return to their original shape after the force that stops the deformed (steel is elastic springs).
Thermal conductivity and thermal insulation: Properties are opposite. In the first case, the material lets heat pass through it, and second, the material that prevents heat from happening.
Impermeability to water: It is typical of materials that do not allow water to pass through it (construction materials and textiles).
Fragility and strength: Properties opposite. The first is typical of materials that break easily (ceramics), metals (iron) which are resistant to coast to break them.
Conductivity and electrical insulation: In the first case, the material conducts electricity, the latter prevents this circle.