CBSE Class IX SCIENCE CHEMISTRY Is matter around us pure
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CBSE Class IX SCIENCE CHEMISTRY Is matter around us pure

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CBSE Class IX SCIENCE CHEMISTRY

CBSE Class IX SCIENCE CHEMISTRY
Is matter around us pure

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CBSE Class IX SCIENCE CHEMISTRY Is matter around us pure CBSE Class IX SCIENCE CHEMISTRY Is matter around us pure Presentation Transcript

  • IS MATTER AROUND US PURE Pranav Ghildiyal Roll no. SCIENCE PROJECT
  •  Matter is a general term for the substance of which all physical objects are made, however in practice there is no single correct scientific meaning; each field uses the term in different and often contradictory ways. Whereas "matter" originally (in Aristotelian hylomorphism) referred not to an independent thing, but to a co- dependent "principle," the modern conception is that matter is a "substance“ that is to say, it exists even apart from composing something else. Modern science identifies this "substance" through its physical properties; the most common current definition of matter is anything that has mass and occupies volume. Matter is commonly said to exist in four states ( or phases) : solid, liquid, gas and plasma. However, advances in experimental technique have realized other Phases.
  • The substances which do not have adulteration are known as pure substances. Some are given below. Milk Bread Ghee Jam
  •  A mixture is when two or more different substances are mixed together but are not combined chemically. The molecules of two or more different substances are mixed in the form of mechanical mixtures, solutions, suspensions, and colloids. While there are no chemical changes to its constituents, the physical properties of a mixture such as its melting point, may differ from those of the components. Some mixtures can be separated into their components by mechanical means. There are two types of mixtures. (i) Homogeneous (ii) Heterogeneous
  • HOMOGENEOUS HETEROGENEOUS  Substances that look the same throughout.  Homogeneous substances have one phase and uniform composition.  Example :Alcohol ,wine ,milk  substances in which you can see more than one color or type of matter.  Heterogeneous substances have more than one phase and a non- uniform composition.  Example : Sandy water , orange juice with pulp in it sugar cornstarch.
  • A solution is a homogenous mixture of substances with variable composition. The substance present in the major proportion is called the solvent, whereas the substance present in the minor proportion is called the solute. It is possible to have solutions composed of several solutes. The process of a solute dissolving in a solute is called dissolution. There are three types of solution :-Solid, Liquid, Gas. CHARACTERISTICS OF SOLUTION A solution is something dissolved in something else. By dissolved it mean it needs to have some partials ionized a solid you place in water that dissociates (ions split apart from each other) makes a solution a good solution you can make in your kitchen is a salt-water solution, Put some regular table salt in a glass and stir it and you will notice the salt "disappears" what happens is the sodium ions and the chloride Ions separate and 'hide' between water molecules. .
  • Types of solution Solid • Solid substance have definite shape, • Fixed volumes, • Are rigid. • Cannot be compressed Liquid • Liquid substances doesn’t have definite shape , • Definite volume, are Non -rigid. • Cannot be compressed. Gas • No definite shape. • No definite volume. Are not at all rigid. • Can be easily compressed
  • •A solution is a homogeneous mixture. The particles of a solution are smaller then 1nm in diameter, so they cannot be seen with naked eye. •Because of very small particle size, they do not scatter a beam of light passing through the solution. So, the path of the light is not visible in the solution.The solute particles cannot be separated from the mixture by the process of filtration. The solute particles do not settle down when left undisturbed. That is, a solution is stable.Many reactions do not occur until the solid reactants are dissolved to make a solution.The solvent is present in greater amount in greater amount.
  • SOLVENT SOLUTE  The component of the solution that dissolves the other component in it (usually the component present in larger amount) is called the solvent.  Present on a greater proportion in the solution.  Dispersed phase.  Solution may or may not be in the same state of matter as the solute.  The component of the solution that is dissolved in the solvent (usually the component present in lesser quantity ) is the solute.  Present in lesser proportion in the solution.  Medium of dispersion solute.  Solution will be in the same state of matter as the solute.
  • The concentration of a solution refers to the strength of the solution. Concentration = quantity of solute quantity of solution (not solvent) There are 3 basic ways to express concentration: 1) percentages, 2) very low concentrations, 3) molar concentrations 1) Percentage (%) concentration can be in V/V, W/W, or W/V 2)Expressing concentrations in parts per million (ppm) requires the unit on top to be 1,000,000 times smaller than the unit on the bottom. 3) Molar concentration is the most commonly used in chemistry. Ensure that units are mol/L.
  •  A suspension is a heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometer. The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. Unlike colloids, suspensions will eventually settle. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the suspended particles are smaller and do not settle. Colloids and suspensions are different from solutions, in which the dissolved substance (solute) does not exist as a solid, and solvent and solute are homogeneously mixed.
  •  The particles of suspension can be seen by the naked eye.  The particles of a suspension scatter a beam of light passing through it and makes its path visible  The solute particles settle down when a suspension is left undisturbed, that is, a suspension is unstable
  •  colloid is a type of mixture in which one substance is dispersed evenly throughout another. A colloidal system consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase . A colloidal system may be solid, liquid, or gaseous.  Many familiar substances are colloids, as shown in the chart below. As well as these naturally occurring colloids, modern chemical process industries utilize high shear mixing technology to create novel colloids.  Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color.
  •  There are many types of colloids :- Aerosol(gas +liquid/solid e.g. fog and smoke) Foam(liquid +gas e.g. whipped cream) Emulsion(liquid +liquid e.g. milk) Sol(liquid + solid e.g. paint) Solid foam(solid + gas e.g. marshmallow) Solid emulsion(solid + liquid, e.g. cheese) Solid Sol(solid + solid e.g. pearl.)
  •  By a colloidal solution one understands a solution, in which the solved particles are present in such a small grain size that they cannot be separated by filtration. The solved particles are larger than molecules, but they are smaller than fillers in suspensions. Therefore these colloidal solutions behave partly like genuine solutions. In order to keep such colloidal solutions stable and to prevent precipitations, wetting and dispersing agents as well as other additives are added. In foundries, colloidal graphite solutions are used as die coatings.
  •  One property of colloid systems that distinguishes them from true solutions is that colloidal particles scatter light. If a beam of light, passes through a colloid, the light is reflected by the colloidal particles and the path of the light can i.e., be observed.  A colloid is a heterogeneous mixture.  The size of particles of a colloid is too small to be individually seen by naked eye.  Colloids do not settle down when left un disturbed, that is, a colloid is quite unstable.
  • Common examples of colloids Dispersed phase Liquid Solid Gas Liquid Solid Gas Liquid Solid Dispersing space Gas Gas Liquid Liquid Liquid Solid Solid Solid Example Fog, clouds, mist Smoke, automobile exhaust Shaving cream Milk, face cream Milk of magnesia, mud Foam, rubber, sponge, Pumice Jelly, cheese, butter Coloured gem stone,glass Type Aerosol Aerosol Foam Emulsion Sol Foam Gel Solid Sol
  •  A pure substance is a substance where there is only one kind of matter present and only one kind of particles. Where as a mixture is an impure substance that has two or more kinds of matter present and two or more kinds of particles present. Also a pure substance has fixed, sharp melting and boiling points and a mixtures varies.
  •  Substance consisting of atoms which all have the same number of protons – i.e. the same atomic number. Elements are chemically the simplest substances and hence cannot be broken down further using chemical methods. At 75 percent, hydrogen is the most abundant element in the universe, followed by helium at 23 percent and oxygen at 1 percent. The other elements make up the remaining 1percent. In the earth's crust, oxygen (47 %) is the most abundant element, followed by silicon (28 %) and aluminum (8 %). 75% 23% 1% 1% Elements in the universe hydrogen helium oxygen others
  •  In chemistry, a compound is a substance that results from a combination of two or more different chemical element s, in such a way that the atoms of the different elements are held together by chemical bonds that are difficult to break. These bonds form as a result of the sharing or exchange of electron s among the atoms. The smallest unbreakable unit of a compound is called a molecule.
  • IONIC COMPOUNDS MOLECULAR COMPOUNDS Ionic compounds are formed when metallic elements from The left-hand side of the Periodic Table react with non metallic elements from the right-hand side of the Table. Ionic compounds have high melting and boiling points. Many ionic compounds are soluble in water.  Molecular compounds form ed when two or more nonmetal atoms form units that are called molecules. Molecular compounds generally have low melting and boiling points. Molecular compounds do not conduct electricity in the solid form or in the liquid form. Some molecular compounds dissolve in water and some do not.
  • MIXTURES COMPOUNDS A mixture is when two or more different substances are mixed together but are not combined chemically. The molecules of two or more different substances are Mixed In the form of mechanical mixtures, solutions, suspensions, and colloids. While there are no chemical changes to its constituents, the physical properties of a mixture such as its melting point, may differ from those of the components. In chemistry, a compound is a substance that results from a combination of two or more different chemical element s, in such a way that the atom s of the different elements are held together by chemical bonds that are difficult to break. These bonds form as a result of the sharing or exchange of electron s among the atoms. The smallest unbreakable unit of a compound is called a molecule .
  • Alloys Alloys are mixture of two or more metals or a non metal and cannot be separated into their components by physical methods. But still, an alloy is considered as a mixture because it shows properties of its constituents and can have variable composition. For example, brass is a mixture of approximately 30% zinc and 70% copper Elements  The number of elements known at present are more than Hundred. Ninety-two elements are naturally Occurring and the rest are man- made.  Majority of elements are solid.  Eleven elements are in gaseous state at room temperature. Two elements are liquid at room Temperature – mercury and Bromine.  Elements, gallium and cesium become liquid at a temperature slightly above room temperature (303K)