CHEMystery: The Periodic Table of the Elements

<BODY BGCOLOR=#000000 TEXT=#FFFFFF LINK=#FF7F00 VLINK=#00CFCF ALINK=#FFFF00> <B><SMALL> <A HREF=".." TARGET="_parent">Return</A> to the Main CHEMystery Page.<BR> <A HREF="../pertable" TARGET="_parent">Return</A> to the Periodic Table of the Elements<BR> </SMALL></B> <H1><FONT FACE="Arial"><I>Element 20 - Calcium (Ca) <A HREF="20.wav"><IMG SRC="sound.gif" ALT="sound" BORDER=0 ALIGN=top></A></I></FONT></H1> From <I>calx</I>. or lime--an oxide of calcium; discovered 1808; fifth most abundant in the earth's crust. Its presence in our bodies is essential. Normal quota in an adult is about two pounds, mostly in the teeth and bones. Calcium also plays a role in regulating the heartbeat. <HR> <CENTER><TABLE BORDER=1 CELLPADDING=2 CELLSPACING=2> <TR><TD COLSPAN=2><CENTER><H3><FONT FACE="Arial">Properties</FONT></H3></CENTER></TD></TR> <TR> <TD><A HREF="../reference/glossary.html#atomicnumber" TARGET="_parent">Atomic Number</A>:</TD> <TD>20<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#atomicweight" TARGET="_parent">Atomic Weight</A>:</TD> <TD>40.078<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronconfiguration" TARGET="_parent">Electron Configuration</A> (at ground state):</TD> <TD>1s<SUP>2</SUP>2s<SUP>2</SUP>2p<SUP>6</SUP>3s<SUP>2</SUP>3p<SUP>6</SUP>4s<SUP>2</SUP><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#oxidationstate" TARGET="_parent">Oxidation States</A> (Bold most stable):</TD> <TD><B>+2</B><BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#boilingpoint" TARGET="_parent">Boiling Point</A> (K):</TD> <TD>1757<BR></TD> </TR> <TR> <TD>Melting Point (K):</TD> <TD>1112<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#density" TARGET="_parent">Density</A> (at 300K -- g/cm<SUP>3</SUP>):</TD> <TD>1.55<BR></TD> </TR> <TR> <TD>Atomic Volume (at 300K -- cm<SUP>3</SUP>/mol) <TD>29.90<BR></TD> </TR> <TR> <TD>Number of stable <A HREF="../reference/glossary.html#isotopes" TARGET="_parent">isotopes</A>:</TD> <TD>6<BR></TD> </TR> <TR> <TD> <A HREF="../reference/glossary.html#massnumber" TARGET="_parent">Mass Number</A> (Bold naturally occurring) -- <A HREF="../reference/glossary.html#halflife" TARGET="_parent">Half-Life</A> -- <A HREF="../reference/glossary.html#radioactivedisintegrationseries" TARGET="_parent">Disintigration Type</A>: </TD> <TD> <B>45</B> -- 165 days -- <A HREF="../reference/glossary.html#betaparticle" TARGET="_parent">beta particle</A> (<A HREF="../reference/glossary.html#electron" TARGET="_parent">electron</A>) emission<BR> </TD> </TR> <TR> <TD>Covalent Radius (Å):</TD> <TD>1.74<BR></TD> </TR> <TR> <TD>Atomic Radius (Å):</TD> <TD>1.97<BR></TD> </TR> <TR> <TD>First <A HREF="../reference/glossary.html#ionizationenergy" TARGET="_parent">Ionization Potential</A> (V):</TD> <TD>6.113<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#electronegativity" TARGET="_parent">Electronegativity</A> (Pauling's):</TD> <TD>1.00<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#specificheat" TARGET="_parent">Specific Heat</A> Capacity (at 300K -- J g<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>0.647<BR></TD> </TR> <TR> <TD>Heat of Vaporization (kJ/mol):</TD> <TD>154.67<BR></TD> </TR> <TR> <TD>Heat of Fusion (kJ/mol):</TD> <TD>8.53<BR></TD> </TR> <TR> <TD>Electrical Conductivity (at 293K for polycrystalline material -- 10<SUP>6</SUP> <IMG SRC="../misc/oomega.gif" ALT="(ohms)"><SUP>-1</SUP> cm<SUP>-1</SUP>):</TD> <TD>31.3<BR></TD> </TR> <TR> <TD>Thermal Conductivity (at 300K -- W m<SUP>-1</SUP> K<SUP>-1</SUP>):</TD> <TD>200<BR></TD> </TR> <TR> <TD>Crystal Structure:</TD> <TD><IMG SRC="cubic-face.gif" ALIGN=middle> Cubic, face centered<BR></TD> </TR> <TR> <TD><A HREF="../reference/glossary.html#acid" TARGET="_parent">Acid</A>-<A HREF="../reference/glossary.html#base" TARGET="_parent">Base</A> Properties:</TD> <TD><IMG SRC="very-basic.gif" ALIGN=middle> Very basic<BR></TD> </TR> </TABLE></CENTER> <HR> <CENTER> <A HREF="ptbl_bar.map"><IMG SRC="ptbl_bar.gif" ALT="The Periodic Table of the Elements" BORDER=0 WIDTH=579 HEIGHT=49 ISMAP></A> </CENTER> </BODY>