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B. RadioactivityThe readioactivity of an element can be described by the following equation:Nt=Noekt(1)whereNtrepresents the radioactivity at some time, t.Norepresents the initialradioactivity, andkis the radioactivity constant. If you take thelnof both sides ofequation(1), we get:lnNt=lnNo-kt(2)Notice that Equation 2 is a linear equation of the formy=mx+b(also called slopeintercept form). Let us express Equation 2 above as follows:lnNt=-kt+lnNoy=mx+bNow we can see that the y-intercept b is equal tolnNo. We can also equate m with -k,which tells us that the slope is negative.Once the value of the radioactivity decay constant k is known, the radioactivity at anyother time (t) can be calculated from the Equation (1).Using the following data for a sample of Uranium-235, plot the natural log (ln) as afunction of time.Table: Radioactivity Experimental DataTime (109Years)Average Radioactivity(Counts per minute)ln(Average Radioactivity)0.0010000.158600.307500.456450.605600.754800.90420xvi
From the graph determine the slope and y-intercept of the line of ”best fit” line throughthe data points.slope:ln(radioactivity)Time(109years)=y-intercept: ln(radioactivity) =What percent of the original sample remain after 1.0 billion (109) years?When you are done with this assignment, submit the following to your instructor:1. The page on Boyl’es Law and the accompanying graph2. The page on radioactivity decay and the the accompanying graphxvii
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Formula WritingName:Given the ions shown, fill in the Table with the appropriate chemical formula.AnionCl-1SO-24CO-23NO-13CationNH+4Ag+Cu2+Ca2+K+Hg2+Fe3+Zn2+Al3+Mg2+Cr3+xx
Write the name of each ion under the ion formula. Then, using the ion names, fill in theTable with the name of the compound formed from each ion pair.AnionCl-1SO-24CO-23NO-13CationNH+4Ag+Cu2+Ca2+K+Hg2+Fe3+Zn2+Al3+Mg2+Cr3+xxi
Name:Fill in the blank in the Table below. Fill in the third and fourth column with the chemicalformula and name, respectively, of the barium salt that contains the anion in the acidformula.Formula ofAcidName of AcidFormula ofBarium SaltName of Barium SaltSulfuric AcidChloric AcidHydrobromic AcidNitric AcidPhosphoric AcidCarbonic AcidFill in the blank in the Table below.Formula ofAcidName of AcidFormula ofAluminumSaltName of AluminumSaltAluminum NitrateAluminum SulfateAluminum HypochloriteAluminum PhosphateAluminum ChlorateAluminum Nitridexxii
Equation WritingName:For each of the following write a balanced chemical equation. An upward pointing arrow() refers to gas formation. A downward pointing arrow () refers to formation ofprecipitate. The triangle (4) for decomposition reactions indicates that heat must beadded for the reaction to occur.

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