Posted by QVGA
What i want to know is whether soil has more airspaces than sand in it? An experiment i read said that add water in sand and soil and afterwards see who's mass/volume decreases more. I'm really stumped and need help!!
Posted by Cycovision
Here you go
http://www.sciencebuddies.org[....]oject_ideas/MatlSci_p024.shtml
The guide is aimed at young kiddies but the science is sound, I remember using a similar procedure in Chemistry when I was doing my 'A' Levels.
Posted by voda_jon
or u could measure equal amounts in beakers, then compress... the one which has least volume after compression would therefore have more air in the spaces me thinks.
Posted by QVGA
thanks. can you tell me the conclusion? is sand more porous than soil?
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[ This Message was edited by: QVGA on 2007-12-06 15:42 ]
Posted by Burgaz
bloody hell do you want them to write the whole project for you too....
Posted by QVGA
is sand more porous than soil?
i just want the answer to that
Posted by QVGA
sand has more air in it than soil, i think i found it.
Posted by Cycovision
Yes it has bigger airspaces, but it's not necessarily more porous! Sand has a porosity of about 34% but clay soil has a porosity of up to 53% according to google and thickypedia.
Posted by fatreg
On 2007-12-06 17:06:30, Cycovision wrote:
Yes it has bigger airspaces, but it's not necessarily more porous! Sand has a porosity of about 34% but clay soil has a porosity of up to 53% according to google and thickypedia.
the porosity of sand fluctuates too, locally Weymouth sand is more porous than that of Lyme Regis (Originates from Normandy), without getting very sad, the sand of Lyme Regis is mixed sized therefore compacts better resulting in less air between grains......
Posted by goldenface
To add to the confusion, some soil naturally contains sand too so it depends on what kind of soil.
My guess is soil would be more porous simply because a kg of soil would be much larger volume wise than a kg of sand, correct me if I'm wrong.
Posted by Cycovision
^^^^^
yeah, I reckon it's one of those trick questions where the answer is the opposite of what you'd think!
Posted by fatreg
Sand has a porousity of about 34% whereas soil is about 20%
Posted by Cycovision
Yeah but what about clay soil? It's technically more porous but gravity, compression and electrostatic charge can make it waterlogged? Or am I wrong? Probably!
Posted by fatreg
you're spot on cyco!
water logging is a big problem in clay. clay is essentially made up of hexagons that when wet tesselate into position as not to allow any water through.