Around The Sun

Atomic system and Periodic Table Elements An element is a primaeval amount that apprisenot be broken down by chemic means to simplier substances. An element consists entirely of atoms. E.g. H, He, O i.e. every(prenominal) the elements in the Periodic Table. Compounds A compound is a substance cool of elements combined in a fixed proportions. Compounds potty further be broken down into simple units by chemical substance means. E.g. 2 water supply (l) ? 2H2(g) + O2(g) Mixtures A mixture is a combination of 2 or more than substances in which the substances retain their identity. A mixture can be separated by physical means. E.g. Air ? H2(l) + O2(l) Symbols of the elements H, He, Li, Be, B, C , N, O, F, Ne, etc.. prone that we have different elements and that they have different properties and characteristics, e.g. He, S, Fe, what is the amount-go of the difference mingled with onw e lement with an another? Atomic Theory of Matter either matter consists of minute, undividable particles called atoms which combine unitedly in respective(a) ways. E.g. water system, O2, CaCO3 Daltons Atomic Theory 1. Matter is quiet of indivisible particles called atoms. 2. Atoms of the kindred element have the corresponding physical and chemical properties. 3. Atoms of different elements have different weights ( smokestackes) 4. Chemical compounds are make up of 2 or more different atoms joined unneurotic in simple, fixed ratios.

The Law of Conservation of Mass In a chemical cha nge, mass is conserved ( centre mass of reac! tants = Total mass of products) E.g FeS ? Fe + S 87.8g 55.8 32g reactant (87.8g products) The Law of unremitting Composition The same compound, no matter how it is prepared, always contains the same elements combined in the same fixed proportion by mass. E.g.2H2 + O2 ? 2H2O % H in H2O = 11.2 % O in H2O = 88.8 Chemical Formulas...If you want to get a full essay, shape it on our website: OrderCustomPaper.com

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