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Performance exam. Part A. Subtract !. M. V. D. Volume of unknown = final vol – beginning vol. Part B. Water evaporating - physical Tearing paper - physical Yogurt fermenting - chemical Ice melting - physical Silver – element
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Part A Subtract! M V D Volume of unknown = final vol – beginning vol
Part B • Water evaporating - physical • Tearing paper - physical • Yogurt fermenting - chemical • Ice melting - physical • Silver – element • Koolaid/air - both HOMOGENOUS mixtures • Water - compound
Part C LOCATION Nucleus Nucleus Negligible Electron cloud
Part D • Chromium electron configuration • 1s2 2s2 2p6 3s2 3p64s2 3d4 • Look for the s and p electrons in the biggest principal energy level to figure out the # of valence electrons • Dot structure:Cr
Part E • Oxidation # is the charge (top of periodic table) • Chalcogens is GROUP 6 • Most reactive metals => ALKALI METALS • Most reactive nonmetals => HALOGENS • Unreactive group - NOBLE GASES • Bromine – liquid (HALOGENS) • Mercury – liquid (TRANSITION METALS)
Sulfur -34 Mass number • Element - S • Protons/electrons – 16 • Neutrons – 18 • Non-metal • Period- 3 • Oxidation # 2- • Valence elecrons - 6
Metals/Nonmetals/Metalloids • Nonmetals – generally gases, right side of periodic table, brittle, dull • Metals – shiny when clean, ductile, left of periodic table, malleable • Metalloids – on stair step line, chemical and physical properties of BOTH metals and non-metals.
Part F Nuclear Chemistry • After 15 days – 10 units • Half-life (time for ½ the sample to decay) – 5 days Time (years) Amount (g) 0 60 15 30 30 15 45 7.5 *60 3.75 5 10 15 20
Nuclear Equations • 24092 • 24092 U 236 90 4 2 He Th + Alpha particle 0 -1 β U 240 93 Np + Beta particle
Part G • KOH – potassium hydroxide • Manganese (IV) Chloride - MnCl4 • Ca3N2 - calcium nitride • Lithium oxide – Li2O • Mg3(PO4)2 - magnesium phosphate • Beryllium fluoride – BeF2 • LiCl - Lithium chloride • Carbon tetrachloride – CCl4
Naming • SnCl2 – Tin (II) Chloride • Sodium hypochlorite – NaClO • SO3 - sulfur trioxide • Calcium nitrate - Ca(NO3)2 • CO – carbon monoxide • P2O5 – diphosphoruspentoxide • CCl4 – carbon tetrachloride • N2O4dinitrogen tetroxide
balancing • 2HgO 2Hg + O2Decomposition • NaCl + AgNO3 NaNO3 + AgClD. Rep • 2Mg + 2HCl MgCl2 + H2 S. Rep • Mg + O2 2MgO Synthesis • NaOH + HCl NaCl + H2O Neutralization