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Chapter 4. Formation of Compounds. Properties of Salt. White solid at room temperature Crystal shaped cubes Hard & brittle Solid salt does not conduct electricity but melted it does Dissolves easily in water & salt water is excellent conductor of electricity. Properties of components.
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Chapter 4 Formation of Compounds
Properties of Salt • White solid at room temperature • Crystal shaped cubes • Hard & brittle • Solid salt does not conduct electricity but melted it does • Dissolves easily in water & salt water is excellent conductor of electricity
Properties of components Sodium • Shiny, silvery-white, soft, solid element • Metallic • Melts at temperatures above 98˚ C • High reactivity Chlorine • Pale green, poisonous gas with choking odor • Slightly soluble in water • Non-metal • High reactivity
Properties of Carbon Dioxide • Colorless, odorless, and tasteless gas • Soluble in water • Water solution is weak conductor of electricity • Relatively stable • Does not support burning
Properties of components Carbon • Nonmetal • Fairly unreactive at room temperature • At higher temperatures is reactive • Burns easily Oxygen • Nonmetal, colorless, odorless, and tasteless gas • Supports burning • Slightly soluble in water • More reactive than carbon • Most abundant element in Earth’s crust
Properties of Water • Occurs in Earth’s environment in all three states of matter • Boils at 100˚C and freezes O ˚C • Pure water does not conduct electricity in any state • Excellent at dissolving other substances called universal solvent • Stable • Acts as medium in which chemical reactions occur
Properties of components Hydrogen • Lightest and most abundant element • Nonmetal, odorless, tasteless, and colorless gas • Reactive • Does not conduct electricity • Slightly soluble in water Oxygen • Nonmetal, colorless, odorless, and tasteless gas • Supports burning • Slightly soluble in water • More reactive than carbon • Most abundant element in Earth’s crust
Octet Rule Atoms become stable by having eight electrons in their outer energy level (or two electrons in the case of some of the smallest atoms)
Properties Ionic Compounds • Form strong, three-dimensional crystal structure • Crystalline solids at room temperature • Hard, rough, and brittle • Attractions between ions are strong • Dissolve in water • Conduct electricity in liquid state Covalent Compounds • Composed of molecules • Liquids or gases at room temperature • Do not conduct electricity in the pure state • Do not dissolve in water • Usually less soluble in water than ionic compounds