MaplePortal/ChemicalIsotope - Maple Help

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 Chemical and Isotope Data

 Introduction

The ScientificConstants package contains chemical data

Use the GetElement command to access the properties of elements in the Periodic Table. For example, let's review the properties of Platinum (Pt).

 > $\mathrm{with}\left(\mathrm{ScientificConstants}\right):$
 > $\mathrm{GetElement}\left(\mathrm{Pt}\right)$
 ${78}{,}{\mathrm{symbol}}{=}{\mathrm{Pt}}{,}{\mathrm{name}}{=}{\mathrm{platinum}}{,}{\mathrm{names}}{=}\left\{{\mathrm{platinum}}\right\}{,}{\mathrm{atomicweight}}{=}\left[{\mathrm{value}}{=}{195.078}{,}{\mathrm{uncertainty}}{=}{0.002}{,}{\mathrm{units}}{=}{\mathrm{amu}}\right]{,}{\mathrm{meltingpoint}}{=}\left[{\mathrm{value}}{=}{2041.55}{,}{\mathrm{uncertainty}}{=}{\mathrm{undefined}}{,}{\mathrm{units}}{=}{K}\right]{,}{\mathrm{boilingpoint}}{=}\left[{\mathrm{value}}{=}{4098.}{,}{\mathrm{uncertainty}}{=}{\mathrm{undefined}}{,}{\mathrm{units}}{=}{K}\right]{,}{\mathrm{electronaffinity}}{=}\left[{\mathrm{value}}{=}{2.128}{,}{\mathrm{uncertainty}}{=}{0.002}{,}{\mathrm{units}}{=}{\mathrm{eV}}\right]{,}{\mathrm{ionizationenergy}}{=}\left[{\mathrm{value}}{=}{8.9587}{,}{\mathrm{uncertainty}}{=}{\mathrm{undefined}}{,}{\mathrm{units}}{=}{\mathrm{eV}}\right]{,}{\mathrm{electronegativity}}{=}\left[{\mathrm{value}}{=}{2.28}{,}{\mathrm{uncertainty}}{=}{\mathrm{undefined}}{,}{\mathrm{units}}{=}{1}\right]{,}{\mathrm{density}}{=}\left[{\mathrm{value}}{=}{21.5}{,}{\mathrm{uncertainty}}{=}{\mathrm{undefined}}{,}{\mathrm{units}}{=}\frac{{g}}{{{\mathrm{cm}}}^{{3}}}\right]$ (1)

You can also extract the standard atomic weight of platinum.

 >
 ${3.239348611}{}{{10}}^{{-25}}{}⟦{\mathrm{kg}}⟧$ (2)

With the GetIsotopes command, you can access all instances of platinum.

 > $\mathrm{GetIsotopes}\left(\mathrm{element}=\mathrm{Pt}\right)$
 ${{\mathrm{Pt}}}_{{168}}{,}{{\mathrm{Pt}}}_{{169}}{,}{{\mathrm{Pt}}}_{{170}}{,}{{\mathrm{Pt}}}_{{171}}{,}{{\mathrm{Pt}}}_{{172}}{,}{{\mathrm{Pt}}}_{{173}}{,}{{\mathrm{Pt}}}_{{174}}{,}{{\mathrm{Pt}}}_{{175}}{,}{{\mathrm{Pt}}}_{{176}}{,}{{\mathrm{Pt}}}_{{177}}{,}{{\mathrm{Pt}}}_{{178}}{,}{{\mathrm{Pt}}}_{{179}}{,}{{\mathrm{Pt}}}_{{180}}{,}{{\mathrm{Pt}}}_{{181}}{,}{{\mathrm{Pt}}}_{{182}}{,}{{\mathrm{Pt}}}_{{183}}{,}{{\mathrm{Pt}}}_{{184}}{,}{{\mathrm{Pt}}}_{{185}}{,}{{\mathrm{Pt}}}_{{186}}{,}{{\mathrm{Pt}}}_{{187}}{,}{{\mathrm{Pt}}}_{{188}}{,}{{\mathrm{Pt}}}_{{189}}{,}{{\mathrm{Pt}}}_{{190}}{,}{{\mathrm{Pt}}}_{{191}}{,}{{\mathrm{Pt}}}_{{192}}{,}{{\mathrm{Pt}}}_{{193}}{,}{{\mathrm{Pt}}}_{{194}}{,}{{\mathrm{Pt}}}_{{195}}{,}{{\mathrm{Pt}}}_{{196}}{,}{{\mathrm{Pt}}}_{{197}}{,}{{\mathrm{Pt}}}_{{198}}{,}{{\mathrm{Pt}}}_{{199}}{,}{{\mathrm{Pt}}}_{{200}}{,}{{\mathrm{Pt}}}_{{201}}{,}{{\mathrm{Pt}}}_{{202}}$ (3)

 Example - Molecular Weight

This example determines how many molecules of caffeine are in a 250 gram sample.

The chemical formula for caffeine is ${C}_{8}{H}_{12}{N}_{4}{\mathrm{O}}_{2}$.  Thus, the molecular weight is:

 >
 ${3.258087476}{}{{10}}^{{-25}}$ (4)

which, in the current default system of units, SI, is measured in kilograms (kg). However, molecular weight is typically expressed in atomic mass units (amu). To convert a measurement between units, use the convert/units function.

 >
 $\mathrm{MW__AMU}{≔}{196.2064800}$ (5)

By definition, the number of atomic mass units per molecule is equal to the number of grams per mole. Hence, divide 250 by the above result.

 >
 ${\mathrm{NumMoles}}{≔}{1.274167907}$ (6)

which is the number of moles in the sample.

To calculate the number of molecules, multiply the above result by Avogadro's constant.



 > $\mathrm{NumMoles}\cdot \mathrm{evalf}\left(\mathrm{Constant}\left(N\left['A'\right]\right)\right)$
 ${7.673220050}{}{{10}}^{{23}}$ (7)

 Example - Radioactive Decay

The following example shows how to plot the decrease in the radioactive decay activity for a sample of radium-229.

The activity is

 >

where, is the initial activity, is the mean lifetime of the isotope, and is the elapsed time.

The mean lifetime is related to the half-life by $\mathrm{λ}=\frac{0.693}{H}$

 >
 ${\mathrm{\lambda }}{≔}{0.002887500000}$ (8)

Plot with ${A}_{0}=1.$

 >