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What is Isobars?

  Atoms of chemical elements having same atomic mass but a different atomic number are called Isobars. The sum of the number of protons and neutrons together form the atomic mass. Therefore, we can also say the number of nucleons present in the nucleus is equal to the atomic mass of an atom. It will have the same number of nucleons. The number of protons and neutrons alone will vary but the number of nucleons or the sum of protons and neutrons in isobars will always be same. Isobars always have different atomic structure because of the difference in atomic numbers. The number of neutrons makes up the difference in the number of nucleons. Therefore, they are always different chemical elements having same atomic masses. Thus, isobar has different chemical properties. For example : Iron and nickel have atomic number 26 and 28 respectively. However, the mass number is 58. Argon and calcium with atomic number 18 and 20, respectively. However, they have the same atomic mass 40.
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Class -IX : Atoms and Molecules

Law of Chemical Combination Given by Lavoisier and Joseph L. Proust as follows: 1. Law of conservation of mass Mass can neither be created nor destroyed in a chemical reaction. e.g. A + B → C + D  Reactants → Products, Mass of reactants = Mass of products 2. Law of constant proportion In a chemical substance the elements are always present in definite proportions by mass. e.g.,  in water, the ratio of the mass of hydrogen to the mass of oxygen is always 1 : 8 respectively. These laws lacked explanation. Hence, John Dalton gave his theory about the matter. He said that the smallest particle of matter is called ‘atom’. Dalton’s Atomic Theory ·        Every matter is made up of very small or tiny particles called atoms. ·        Atoms are not divisible and cannot be created or destroyed in a chemical reaction. ·        All atoms of a given element are same in size, ma...
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What is the definition of melting and boiling point?

Melting point :   Melting point is the temperature at which a solid becomes a liquid at normal atmospheric pressure. Boiling point :   Temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and liquid change to vapor.
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Saturated solutions is the chemical solution containing the maximum concentration of a solute dissolved in the solvent. The additional solute will not dissolve in a saturated solution. Ex :- Sugar solution.
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What are Colloids or Colloidal Solution?

Colloidal solutions, or colloidal suspensions, are nothing but a mixture in which the substances are regularly suspended in a fluid. A colloid is a very tiny and small material that is spread out uniformly all through another substance.  What do you mean by Colloids?   Colloids are mixtures in which microscopically dispersed insoluble particles of one substance are suspended in another substance. The size of the suspended particles in a colloid can range from 1 to 1000 nanometres (10-9 metres).
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What is a chemical reaction?

A Chemical Reaction is a process that occurs when two or more molecules interact to form a new product(s). Compounds that interact to produce new compounds are called reactants whereas the newly formed compounds are called products.
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What is Tyndall effect? Explain with an example.

 'Tyndall effect, also called Tyndall phenomenon, scattering of a beam of light by a medium containing small suspended particles.' Ex - Smoke or Dust in a room, which makes visible a light beam entering a window.  Short-wavelength blue light is scattered more strongly than long-wavelength red light. The Tyndall effect occurs from particles roughly the same size as the wavelength of light. The effect is named for the 19th-century British physicist John Tyndall, who first studied it extensively.                                            or 'The scattering of light by particles in its path is called Tyndall effect.' When a beam of light enters a smoke-filled dark room through a small hole, then its path becomes visible to us. The tiny dust particles present in the air of r...
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