Which element in each pair would have the greater density?
824593
http://chemlab.pc.maricopa.edu/PERIODIC/periodic.html\n\nHere you can click on an element and see facts on it.\n\nCa<Cr<W
359119
look at column 7.  all of the densities appear there in grams/cm3.\n\nhttp://www.science.co.il/PTelements.asp
819588
number of atoms (of each element) on one side equals the other side.
368567
You might be referring to brass, which has a density of 8.5 g/ml.\n\nBronze with 11% tin has a density of 8.1 g/ml.\n\n\nI would guess the brass, since it is more commonly used.
364066
solid-most dense\nliquid-middle dense\ngas- least dense
949928
I think this is an interesting question.  Surprisingly, I think the answer is yes for some properties.  I don't have data in front of me (my books are at the office), but I'll bet that if you compare densities of homologous compounds in a group, you'd find that the density increases along with the density of the main constituent atoms.  I'll also bet that there are spectroscopic properties that are retained -- those relating to the inner shells.  In addition, there are tests used by mineralogists to detect the presence of common constituent metals in different minerals; a common example is the sodium "D" emission that causes a yellow flame in a fire when sodium is present regardless of the counterion.  In inorganic chemistry I seem to remember endless graphs of periodic properties that we used as a mnemonic device, but that was too many years ago to remember them.\n\nIf I wanted to look into it on the internet, I'd do a search on "periodic properties of the elements."  Also, geochemists are wonderful for collecting data and putting together tables of such things, and undergraduate inorganic textbooks may be helpful for finding some as well.
1108940
Well, it doesn't, really, except that since the law of definite composition says that substances always have the same ratio of the same atoms, they're going to have the same properties, including density (mass per unit volume).  Water is always two hydrogen atoms to one oxygen atom, and will always have a density of 1.00 grams per milliliter at 4 degrees Celsius.  Same applies to all other substances.  In terms of it relating directly to volume, though, it doesn't.
945020
If you have your periodic table handy, look at the key for the table, where it will tell you which corner of each element's block has the atomic radius.  You will notice that atomic radius tends to increase as you go down the rows of the table.  Makes sense; More electrons means a larger atom.  As you go from right to left, however, you will see that, in any one row, the radius decreases until you get to about the middle of the row; then the radius begins to increase with the atomic weight.  On any row, the element at the left end (lower atomic weight) has a larger diameter than the one on the right end (higher atomic weight).  All of this out of the way, Beryllium is larger than Carbon, which is in turn, larger than Nitrogen.
153892
because a gas's moleules are all spread out and in liquid they are all together, and a solid is still more dense, because they are packed even tighter together
827403
Density is a function of two properties of matter- mass and volume.  So you're looking for a material that packs a lot of mass into a small space.  Probably the first hurdle the material has to clear is that it has to pe denser than itself in liquid form.  This is true of most materials that can legitimately have both a solid and liquid form, as the particles "pack in" closer together when they solidify and "spread out" as they liquify.  However, there are exceptions, like water, where the solid form is less dense than the liquid form (which is why ice floats).\n\nGenerally, as you move further up the periodic table into higher atomic numbers, elements get more dense (though exceptions certainly exist).  If you go very far up into the periodic table into say the Actinides (Uranium for example) you get into solids (largely unstable and radioactive, but solids nonetheless) that are extremely dense.  In theory however, at a high enough temperature you could possibly go further up the periodic table, heat the material to its melting point, and create a liquid that could potentially be more dense.
984240
The atomic radii for Cr, Mn, Fe, Co, Ni, and Cu are\n\nCr: 125 pm\nMn: 137 pm\nFe: 124 pm\nCo: 125 pm\nNi: 125 pm\nCu: 128 pm\n\nSo, you can see, there is a bit difference between their sizes. Although among them, Cr, Co, Ni, and Cu do have very similar atomic radius. \n\nThe reason that these elements have similar radius is due to their electron configurations. So, let's look at their corresponding electron configuration first (hope you know what I am referring to) :\n\nCr: [Ar] 3d5 4s1\nMn: [Ar] 3d5 4s2\nFe: [Ar] 3d6 4s2\nCo: [Ar] 3d7 4s2\nNi: [Ar] 3d8 4s2\nCu: [Ar] 3d10 4s1\n\nAs you may realize, the major difference between their electron configuration is mainly in the "3d" orbital, which has a quantum number (n) of 3; this 3d orbital has a smaller radius than the next orbital, 4s. The reason why 4s orbital is filled BEFORE 3d is due to the lower energy level of 4s compared to 3d.\n\nIn short, the major reason why these elements have similar radii is because the newly added electrons are not added to the "outermost electron shell", instead, they are added to the "inner electron shell". Therefore, no SIGNIFICANT changes to their radius.
839048
a.  Expanded shell/with 6 pairs of electrons around the central molecule.\n\nb.  Expanded octet with four shared pairs and one unshared pair.\n\nc.  Not sure but free radical with one double bond between an oxygen and and Cl.
282227
http://www.answers.com/topic/density?method=22\nhttp://www.reference.com/search?q=density
782736
If ideal gas law is obeyed...\n\ndensity = mass/V == n/V\n\nPV = nRT\nP = (n/V)RT\n\nIf temp is held constant then increasing density increases pressure.
162268
The density of the fluid and the density of the object.
809648
Nitrogen might be what you are looking for as it is a gas and is next to Oxygen in the periodic table so it has similar mass.\n\nBut as the person above has said, some kind of gaseous sulfur would have the closest properties to oxygen.
788506
b. electrons\n\nI really hope you are trying to answer these first before you put them on here because although we are all certainly willing to help you, you are not going to gain anything from just having the answers given to you.  You really need to try and learn this stuff.