mercury has higher density than water. does this mean that the molecules of Fe are heavier than of H2O?explain
828588
Both points expressed above are true. A molecule of Hg is indeed heavier that a molecule of air. \n\nBut to say that comparing density will tell how molecular weight compares will not always be true. Density is weight (or mass, it's expressed both ways) per volume so it could be that the density difference is because of how close together the molecules are. \n\nExample: Argon (atomic weight - almost 40) is a gas in normal conditions. It's less dense than water (molecular weight - about 18).
251316
It expands.  \n\nHere's an interesting point... becauase it expands, the same molecules of water take up more space as a solid than as a liquid, so it's less dense.  If it contracted (like most other things do when they go from liquid to solid) it would take up less space and be more dense... so frozen water would be heavier than liquid water.  If that were the case, ice would sink, which would be a serious bummer for fish.  As it is, since water expands, solid water (ice) is lighter than liquid water, so it floats - a serious bummer for the Titanic, but a good thing for cold drinks and fishies.\n\nI love this stuff.
323097
Ice has a lower density than water. When water freezes, the way in which the molecules rearrange to make a solid means that they are slightly further apart than in liquid water. Since density = mass/volume, and in ice there is slightly less mass in the same volume, ice is less dense.\n\nTherefore, because of Archimedes' buoyancy principle (the upward force on an object in liquid is equal to the mass of substance *displaced* by the object), ice floats. The ice displaces a volume of water equal to the volume of ice, but that volume of water has more mass than the same volume of ice, so the upward force is greater than the mass of ice. So the ice floats.
748523
Saturn has a density less than water.  It's density is 0.6873 g/cm^3.  Water has a density of 1g/cm^3.
583824
ice has less density than water.  the H2O bonds in ice are in a crystal lattice structure and there are small bits of air trapped between them.
192094
um. well i would assume itz cuz some of it has a lower density than water and some has a higher density? lower density meanz more holes and stuff in it and higher density means   packed more tightly? hahah. why do you care?
433818
Water provides more force than air because it is\ndenser and thus has more mass:\n\nF = ma \n\nd = m / volume
420597
Franpal is correct, hydrogen and oxygen.  If you're thinking of a D, it may be 'heavy water', which has Deuterium rather than hydrogen (an isotope of hydrogen).
540040
mercury is the heaviest medal/ water is hydrogen and oxygen
903700
That is definitely not correct!!\n\nFor example water (H20) is very very different from the two gases that make it namely hydrogen (H2) and oxygen (O2)
783545
Like the Earth, Mercury has an iron core. But Mercury's core occupies proportionately more (3/4) of the planet's diameter than Earth's does (about half). You can think of Mercury as a metal ball the size of the Moon surrounded by about 700 kilometers (430 miles) of rocky crust. The large relative size of Mercury's core makes it the most iron-rich planet in the solar system, with iron accounting for 65-70% of the planet's mass. Mercury's abundance of iron resulted from its position near the Sun. When the planets were forming out of the same cloud of gas and dust as the Sun, the temperatures in the warm inner regions of the primordial solar nebula were so high that iron-rich minerals were just about the only ones that could condense into solids. Farther away from the Sun, other minerals could also condense. Thus the iron content of the rocky planets in the solar system decreases with increasing distance from the Sun.\n\nMercury's iron core may also be responsible for one of the most surprising findings from Mariner 10 — the planet's weak magnetic field, 100 times weaker than Earth's. Astronomers and geologists are still trying to figure out what causes Mercury's field. In the case of the Earth, rapid rotation of its molten iron core generates electrical currents which produce the Earth's magnetic field. But Mercury is so small, astronomers had assumed its core had cooled and solidified. Plus, it rotates too slowly to generate a magnetic field the way the Earth does. Or so they thought. Perhaps Mercury's core is still partially liquid, or perhaps the magnetic field is "left over'' from an earlier time when the iron core was molten. Astronomers continue to work on this puzzle.
227694
In pure water, the molecules particpate in Hydrogen Bonding; positively polarized hydrogen nuclei are attracted to negatively charged electron clouds. \n\nThese hydrogen bonds hold water molecules together in the liquid phase and so explain why water expands, rather than contracts, when it freezes.\n\nWhen glucose is added to water it interferes with the hydrogen bonding. Effectively, a proportion of the bonds are broken. It requires energy to break bonds (think of breaking a twig--you have to put some energy in to the twig to break it) and that energy has to come from somewhere: it gets sucked out of the immeadiate environment--the glass.
379947
MY GOD!  Don't answer if you don't have a clue.\nA) False - water is exactly 1g/cm3\nB) False - ice floats, thus less dense\nC) False - Water is made of two elements (Hydrogen and Oxygen), thus it cannot be an element itself.\nD) True - The mass of water does not change when it is frozen, melted or heated into steam.  It is still H2O.  No atoms were split or made!\nE) False
444934
At room temperature, the density of mercury is 13.54562 greater than the density of water, and decreases slightly as the mercury is heated.\n\nA gallon of water wieghs exactly 8 pounds, so a gallon of mercury at room temperature would weigh 13.54562 times as much.
973894
float as mercury has a density of about 13.6gm/cc and iron much lesser 7.85gm/cc. Mass is immaterial as  in a sufficient quantity of mercury even a 1000000000000kg iron ball will float
108432
Boats do NOT displace more water than they weigh - the amount of water displaced is EQUAL to the weight of the boat. Salt water is heavier per cubic meter than pure water or fresh water, so a smaller amount of salt water would be displaced for the same weight boat. If the density of the solution was extremely high, as in mercury, the boat would appear to sit on top of the liquid.
180387
heavy water is about 10% heavier then regular water.  \n\nDensity of heavy water = 1.1056 g/ml \nDensity of regular water = 0.9982 g/ml\n\nYou can calculate the conversions to gallons.\n\nAnd oh yah that earlier guy is an idiot.  Heavy Water is not radioactive.  It is a stable molecule that is used in nuclear reactors.  B/c of its greater density it is perfect for the control of nuclear reactions.