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Standard 9 Chemistry Factors affecting rate of chemical reactions
Factors affecting rate of chemical reactions 1. Nature of reactants 2.Concentration of reactants 3.Surface reaof reactants 4. Temperature 5. Presence of catalyst
Unit Test Standard 9
STANDARD 9 UNIT TEST STRUCTURE OF ATOM 1. Which particle in an atom is having positive charge? a. proton b. electron c. neutron d. none of these 27 2.The symbol of an element is P . 13 Find the number of neutrons.(Write only number) 3.Who discovered electron? 4.Who introduced atomic theory? 5.Electronic configuration of an element is 2 8 5. What is its atomic number? 6. The maximum number of electrons that can be accomodated in the outermost shell of an atom? 7.Name the shell closest to the nucleus. 8.. Bohr model of an atom is given. Find its a. Atomic number b. Number of shells c.Number of electrons in the outermost shell
Chemistry Standard 8 Assignment
St. MARY’S C G H S S ERNAKULAM Std 8 Chemistry test paper chapter 1 & 2 1.Solids that easily change into gases without changing into liquids are called ................... substances a. superfluid b. volatile c.sublimable 2.Change of gas into liquid is called ............................. a. liquifaction b. sublimation c. condensation 3.Spontaneous mixing of different particles having freedom of movement is called ................... a. distillation b.diffusion c. evaporation 4. More than one solute dissolved in the same solvent can be separated by .......................... a. chromatography b. centrifugation 5.Insoluble particles in a liquid mixture can be separated on the basis of their mass difference using the method .......................................... a. separating funnel b. centrifugation 6. When liquid changesinto gas force of attraction between molecules .............................. a...