# Calcium's a Metal??? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 26, 2008, 4:49pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323 "2008-08-26T16:49:22Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lobsang](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobsang/32/4067_2.png) [@Lobsang](https://boards.straightdope.com/u/Lobsang)\ **Post date:** [August 26, 2008, 4:49pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/1 "2008-08-26T16:49:22Z")
I didn’t know this until now. :smack: I always associated ‘Calcium’ with edibility and specifically milk. I almost never associate metal with food! When you drink milk you’re drinking metal! AHHHH! 😃 What obvious stuff did you only find out recetnly, or at far too late an age? ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [August 26, 2008, 4:50pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/2 "2008-08-26T16:50:31Z")
[QUOTE=Lobsang] I always associated ‘Calcium’ with edibility and specifically milk. I almost never associate metal with food! When you drink milk you’re drinking metal! AHHHH! ? [/QUOTE] Don’t forget your iron supplements. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [August 26, 2008, 4:58pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/3 "2008-08-26T16:58:40Z")
I remember in an HG Wells book, he postulated calcium-aluminium alloys for airships of the future. There must be a reason why calcium is not used in alloys now. Too reactive? Too expensive? Supply tied up by the dairy industry? Come to think of it, isn’t limestone calcium carbonate? [Yes.](http://en.wikipedia.org/wiki/Limestone) ---
**Author:** ![Steve\_MB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steve_mb/32/5339_2.png) [@Steve\_MB](https://boards.straightdope.com/u/Steve_MB)\ **Post date:** [August 26, 2008, 5:03pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/4 "2008-08-26T17:03:30Z")
[QUOTE=Sunspace] I remember in an HG Wells book, he postulated calcium-aluminium alloys for airships of the future. There must be a reason why calcium is not used in alloys now. Too reactive? Too expensive? Supply tied up by the dairy industry? Come to think of it, isn’t limestone calcium carbonate? [Yes.](http://en.wikipedia.org/wiki/Limestone) [/QUOTE] Too reactive, basically. (Aluminum is also highly reactive, but it forms a tough aluminum oxide skin a molecule or two thick, protecting the bulk of the metal.) ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [August 26, 2008, 5:10pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/5 "2008-08-26T17:10:21Z")
Calcium’s one of those obnoxious metals that reacts vigorously when exposed to water, although not quite as vigorously as sodium or potassium (also metals). See [here](http://www.angelo.edu/faculty/kboudrea/demos/calcium_H2O/calcium_H2O.htm) for some photos. ---
**Author:** ![nofloyd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nofloyd/32/2870_2.png) [@nofloyd](https://boards.straightdope.com/u/nofloyd)\ **Post date:** [August 26, 2008, 5:15pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/6 "2008-08-26T17:15:53Z")
I remember a general rule that elements ending in -ium are likely to be metals. Not helium though. But sodium, potassium and magnesium are metals. ---
**Author:** ![Bosstone](https://avatars.discourse-cdn.com/v4/letter/b/22d042/32.png) [@Bosstone](https://boards.straightdope.com/u/Bosstone)\ **Post date:** [August 26, 2008, 5:17pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/7 "2008-08-26T17:17:12Z")
Salt is a rock. Chew on that. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [August 26, 2008, 5:22pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/8 "2008-08-26T17:22:59Z")
Calcium, magnesium, lithium, sodium, potassium, etc. are all metals. However, since they are very reactive, they are not usually encountered in metallic form. In fact, many are so reactive that they react violently with water. They are therefore found either as part of a compound (e.g. sodium chloride) or in ionic form. The calcium in your milk is not in the metallic state. It is in the ionic form. Calcium pills are actually calcium carbonate. ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [August 26, 2008, 5:24pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/9 "2008-08-26T17:24:37Z")
So our skeletons are metal? ---
**Author:** ![appleciders](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@appleciders](https://boards.straightdope.com/u/appleciders)\ **Post date:** [August 26, 2008, 5:26pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/10 "2008-08-26T17:26:23Z")
“Metal” to a chemist basically means that the element resides on the left-hand side of the periodic table. If you saw a hunk of pure calcium, you’d understand why- it’s shiny and metallic looking, at least before it oxidizes. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [August 26, 2008, 5:39pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/11 "2008-08-26T17:39:37Z")
[QUOTE=control-z] So our skeletons are metal? [/QUOTE] No–the calcium in your bones is not in the metallic form. It is part of an ionic compound called [hydroxylapatite](http://en.wikipedia.org/wiki/Hydroxylapatite), which is a form of calcium phosphate. When metals are combined into an ionic compound, they no longer exhibit metallic properties. Pure iron is metallic (i.e. shiny and conductive). Iron oxide (rust) is not. Pure sodium is metallic. Sodium chloride is not. Pure calcium is metallic. Calcium compounds are not. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [August 26, 2008, 5:48pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/12 "2008-08-26T17:48:22Z")
Hydrogen is also a metal. ---
**Author:** ![Mindfield](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mindfield/32/19759_2.png) [@Mindfield](https://boards.straightdope.com/u/Mindfield)\ **Post date:** [August 26, 2008, 5:55pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/13 "2008-08-26T17:55:11Z")
A nice [video on calcium](http://www.periodicvideos.com/#), in which they talk about calcium being used in early lighting aparatus, which kind of puts a bit of truth to the old joke about filling up the headlight fluid. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [August 26, 2008, 6:15pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/14 "2008-08-26T18:15:22Z")
> [@](#): > > A nice video on calcium, in which they talk about calcium being used in early lighting aparatus, which kind of puts a bit of truth to the old joke about filling up the headlight fluid. I haven’t watched the video, but that’s undoubtedly _calcium carbide_. When you add water to it (slowly) you create carcium carbonate and acetylene. They used to use it in mining lamps – a slow drip of water from an upper reservoir on a lower container full of carbide powder produced a stream od acetylene gas that fed a flame at the center of a reflector. I have one of these lamps that a friend fished out of a lake. The calcium carbide was essentially a transportable form of flammable gas. > **[Carbide lamp](https://en.wikipedia.org/wiki/Carbide_lamp)** > > A carbide lamp or acetylene gas lamp is a simple lamp that produces and burns acetylene (C2H2), which is created by the reaction of calcium carbide (CaC2) with water (H2O). > Acetylene gas lamps were used to illuminate buildings, as lighthouse beacons, and as headlights on motor-cars and bicycles. Portable acetylene gas lamps, worn on the hat or carried by hand, were widely used in mining in the early twentieth century. They are still employed by cavers, hunters, and cataphiles. > In 1892, Thomas W... ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [August 26, 2008, 6:28pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/15 "2008-08-26T18:28:13Z")
[QUOTE=Lobsang] I didn’t know this until now. :smack: I always associated ‘Calcium’ with edibility and specifically milk. I almost never associate metal with food! [/QUOTE] The iron in your breakfast cereal is tiny iron shavings. If you run a magnet over enough cereal, it will get fuzzy. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [August 26, 2008, 7:10pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/16 "2008-08-26T19:10:49Z")
[QUOTE=Alessan] Hydrogen is also a metal. [/QUOTE] Not according to the Wikipedia: > **[Periodic table](https://en.wikipedia.org/wiki/Periodic_table)** > > The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). An icon of chemistry, the periodic table is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called... ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [August 26, 2008, 7:14pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/17 "2008-08-26T19:14:55Z")
> [@](#): > > Not according to the Wikipedia: > > [Periodic table - Wikipedia](http://en.wikipedia.org/wiki/Periodic_table) A reminder that Wikipedia is not the be-all and end-all of knowledge. Googling “Metallic hydrogen” gives about a quarter of a million hits. Including this one from Wikipedia: > **[Metallic hydrogen](https://en.wikipedia.org/wiki/Metallic_hydrogen)** > > Metallic hydrogen is a phase of hydrogen in which it behaves like an electrical conductor. This phase was predicted in 1935 on theoretical grounds by Eugene Wigner and Hillard Bell Huntington. > At high pressure and temperatures, metallic hydrogen can exist as a partial liquid rather than a solid. It is thought to appear in large quantities in the hot and gravitationally compressed interiors of Jupiter and Saturn, as well as in some exoplanets. > Though generally placed atop the alkali metal column... ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [August 26, 2008, 7:17pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/18 "2008-08-26T19:17:08Z")
[QUOTE=Sage Rat] Not according to the Wikipedia: > **[Periodic table](https://en.wikipedia.org/wiki/Periodic_table)** > > The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). An icon of chemistry, the periodic table is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called... [/QUOTE] I take that back: > **[Metallic hydrogen](https://en.wikipedia.org/wiki/Metallic_hydrogen)** > > Metallic hydrogen is a phase of hydrogen in which it behaves like an electrical conductor. This phase was predicted in 1935 on theoretical grounds by Eugene Wigner and Hillard Bell Huntington. > At high pressure and temperatures, metallic hydrogen can exist as a partial liquid rather than a solid. It is thought to appear in large quantities in the hot and gravitationally compressed interiors of Jupiter and Saturn, as well as in some exoplanets. > Though generally placed atop the alkali metal column... ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [August 26, 2008, 7:19pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/19 "2008-08-26T19:19:56Z")
The alkali metals! Very cool stuff. I find it interesting most people don’t know calcium is in the same metallic group as potassium, sodium, magnesium, etc. The heavier those elements get, the more reactive they are to oxygen (fun with water). But yeh, as mentioned, a lot of the metals in our diet aren’t in elemental form, but are molecular compounds. That’s why a lot of people think pure calcium is a chalky, white substance… in the form of the naturally occurring calcium carbonate (CaCO3). ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [August 26, 2008, 7:23pm UTC](https://boards.straightdope.com/t/calciums-a-metal/461323/20 "2008-08-26T19:23:58Z")
[QUOTE=Lobsang] What obvious stuff did you only find out recetnly, or at far too late an age? [/QUOTE] That the gold leafing around the brim and handle of a rarely used coffee mug, full of joe, would light up like a christmas tree, when I pop it in the mike for a warm up. Why, just this morning, in fact. :eek: [Next page](https://boards.straightdope.com/t/calciums-a-metal/461323.md?page=2)