Molecules Definition and 561 Threads

  1. darksat

    Infrared energy absorption of H20 molecules as a percentage of energy

    I eventually managed to find that a CO2 molecule can absorb about 8% of infrared energy passing through it that's radiated from Earth but its actually been incredibly hard to find a comparable figure for H2O molecules. Has anyone got a percentage figure for H2O in the form of atmospheric water...
  2. H

    Why are most molecules in the singlet state instead of the triplet state?

    Most molecules are in singlet ground state which is of higher energy than triplet lower energy state .According to thermodynamics molecule tend to remain in lower energy state.Therefore,I presume molecules should remain in triplet state .Could anyone clarify my point
  3. haushofer

    Sound waves: why do air molecules oscillate?

    Dear all, "Why do air molecules start to oscillate and influence each other such that a wave is forming when you hit e.g. a drum?" High school students asked me this, thinking the air molecules collide like marbles, creating a longitudinal wave. How would you explain this interaction-wise? Any...
  4. I

    I Can Molecular Distances Determine the Volume of Objects?

    Summary: Is there any calculation for distance between molecules to find out the volume of shapes around us? Molecules give shape to everything around us,so I want to know is there anyway to find out volume of shape(like rock)by the distance between molecules?
  5. PainterGuy

    Boltzmann distribution and the number of molecules with a certain velocity

    Hi, You could skip these details and find the main question at the bottom. I added the details for the sake completeness and context. Thanks. Boltzmann distribution of molecular speeds provides an insight into the different speeds the molecules of a gas are moving around with. It provides you...
  6. L

    I Best models to describe molecules

    Molecules don't really look like this with clearly defined objects and outlines. Remember that in the double slit experiments, we can't even model what happens between measurements, like how the electron behave between emitter and detector. So what is the best model to describe them? How...
  7. V

    The speed of molecules and a machine that sorts them

    Is there any device that can sort the particles of some medium according to the speed at which they move in the medium or something like that? As far as I know, there's a machine that can sort particles by charge through a magnetic field. Is there such a thing for speeds and charged / uncharged...
  8. E

    Heat Storage Capacity of CO2 molecules

    I am a science hobbyist and working on a paper to illustrate the impact of CO2 on Global Warming. Question – What is the Storage Capacity in joules, of one molecule of CO2 @ 20c/68f/293k. In other words, what is the maximum amount of IR energy that one molecule of CO2 can store at this...
  9. S

    Average speed of molecules in a Fermi gas

    My first most obvious attempt was to use the relation ##<\epsilon> = \frac{3}{5}\epsilon_F## and the formula for kinetic energy, but this doesn't give the right answer and I'm frankly not sure why that's the case. My other idea was to use the Fermi statistic ##f(\epsilon)## which in this case...
  10. L

    Poles of the self-energy in atoms and molecules

    We can use the method of the Green functions to calculate ioniation potentials and electron affinities of atoms and molecules. These quantities can be determined if we know the self-energy ##\Sigma(E)##, that is a function of the energy ##E##. A matrix element of the self-energy in the basis of...
  11. J

    Chemistry Books where chemists explain how they designed new molecules

    I would like to read historical documents where the chemist that succeded in synthetizing a new molecule explains the process he used to obtain his results. Does that exists? Instead of reading about solving the shrodinger equation in a square potential I would like to read how someone actually...
  12. PORFIRIO I

    Electrons colliding with gas molecules

    My concern is an electron tube. From what I understood so far, gas molecules will have an average velocity derived from the Maxwell distribution, and that velocity will influence in the electron collision frequency. I can't see clearly though how the electron velocity itself in the presence...
  13. Viona

    Average Velocity of gas molecules calculated with a Boltzmann distribution

    Hello What is the meaning of the average velocity of gas molecules calculated by Boltzmann distribution (in kinetic theory of gases)? Does all molecules have the same average velocity?
  14. H

    Why are non-polar molecules attracted to each other?

    Okay guys I have a question that does not make sense to me. My teachers, and even the chem and bio textbooks, have often said that polar molecules bond with each other, and non-polar molecules bond with each other. I do get why polar molecules can form bonds, which is due to the e- arrangement...
  15. HCverma

    Are Cl2, O2 , H2 etc neutral molecules?

    Are Cl2, O2 , H2 etc are nutral molecules? As we know their atoms are neutral such as Cl. It has 17 protons and 17 electrons. Because it has the equal number of protons and electrons, it is a natural element. But when two Cl atoms combine through covalent bond by sharing a pair of electrons...
  16. patric44

    I Is this just a normal fluorescence of glass molecules?

    hi guys i recently had built a HV power supply out of an old Flyback transformer i had laying around , i think it produces about 10KV ~ 15KV not very sure but it could arc at about ( 6mm in air ) , and as you can see i tried to connect it to a 15W smal light bulb ( the positive terminal...
  17. SmugBug

    How many air molecules are there inside the tire?

    Homework Statement A car tire has a volume of 10 L and is inflated to a gauge pressure of 30 psi (207,000 Pa) at 20°C. How many air molecules are there inside the tire?Homework Equations N = PV/ kbT The Attempt at a Solution (207,000 Pa )x (0.01 m3) / (1.38 x 10^-21 x 293) =5.12 x 10^23...
  18. Monsterboy

    How does the velocity of air molecules affect EM waves?

    I would like to know how exactly or if the velocity of air molecules affect the light i.e electromagnetic waves passing through it. Ignoring the effect of pressure and/or temperature differences in the air which might also affect the light (due to changes in refractive index).
  19. DrClaude

    I Did NASA's Curiosity Rover Discover Ancient Organic Matter on Mars?

    NASA Curiosity rover hits organic pay dirt on Mars Scientific article: Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars
  20. BillTre

    Methane and Organic Molecules on Mars

    Curiosity has found seasonal occurrences of methane and some organic molecules on Mars. Both or possible indicators of carbon based life processes, but can have other non-biological explanations. Methane has been intermittently found previously on Mars. However, lacking a continuous long term...
  21. Kenneth Boon Faker

    B Why does bonding occur between atoms?

    If each electron cloud repels other electrons and other atoms, then why can two or more atoms form molecules? Is it to do with negative and positive charges?
  22. steven george

    Average velocity of gas molecules in a container

    Homework Statement An ideal gas with molecules of mass m is contained in a cube with sides of area A. The pressure exerted by the gas on the top of the cube is P, and N molecules hit the top of the cube in a time Δt. What is the average vertical component of the velocity of the gas...
  23. I

    1 volume of hydrogen = how many hydrogen molecules there?

    ''1 volume of hydrogen + 1 volume of hydrogen + 1 volume of oxygen = 2 volumes of water vapor'' Now my questions are as follows: 1. How many hydrogen molecules in 1 volume of hydrogen? 2. How many oxygen molecules in 1 volume of oxygen? 3. how many water vapor molecules in 2 volumes of water...
  24. I

    What to say: "one mole of C atoms" or "one mole of C molecules"?

    As we know, Please point out if I am wrong here one molecule of CO = one mole of CO molecules = 6.223 X 10^23 number of CO molecules If I split one molecule of CO, we get one C and one O. Here are my questions, What to say these ''one C and one O" one mole of C atoms and one mole of O atoms or...
  25. Rensslin

    Find Compound to Break Super Concrete Slab

    So I have a slab made out of super concrete. I drilled holes for something that will expand and pop the slab. But the product for sale is outside my budget for 50 x as much as I need. Does anyone know a compound that will slowly react to expand forcefully enough to break up the slab?
  26. J

    Ideal gas - percentage of fraction of molecules

    Homework Statement Homework EquationsThe Attempt at a Solution Honestly speaking , I have absolutely no idea about this problem .This doesn't happen often .In the KTG chapter , only definition and formula of Average , RMS and Most probable speeds is given . This question is for an...
  27. M

    Can you separate hydrogen and oxygen molecules?

    Is separating hydrogen and oxygen molecules possible? If so, how?
  28. I

    Unicellular functioning molecules inside multicellular cells

    When cells within multicellular organisms started differentiating/specializing, was this handled by a new set of chromosomes developing these functionalities, leaving the DNA that is in charge of unicellular functionality more or less consistent and similar? Or did the original chromosome...
  29. axer

    Chemistry Calculate the number of molecules of O2 when given the number of moles

    Homework Statement After balancing an equation, there are 1.82 moles of O2. Calculate the number of molecules of O2. given moles. Homework EquationsThe Attempt at a Solution in every O2 molecule, there are 2 moles of O. so if the number of moles of O2 molecule is 1.82. then 1.82*2= 3.65...
  30. Pushoam

    Solving Flux of Molecules Problem

    Homework Statement Derive the flux of molecules i.e. no. of molecules striking a surface per unit area per unit time. Homework EquationsThe Attempt at a Solution [/B] Let's say that there are n molecules per unit volume. The no. of molecules which will touch the surface in the +ve x...
  31. A

    How Does Dipole-Dipole Interaction Affect H₂ Molecule's Ground State Energy?

    Homework Statement Consider an ##H_2## molecule where the protons are separated by a wide distance R and both are located on the z-axis. Ignoring the spin degrees of freedom and treating the dipole-dipole interaction as a perturbation, use perturbation theory to estimate an upper limit for the...
  32. D

    How do I draw Lewis Structure Diagrams? +1 More

    Homework Statement : 2 Questions, sorry about this if It adds confusion. 1) How do I go about drawing Lewis Structure Diagrams? I've searched the web, but all I can find, even when they say it's a "Lewis structure" diagram is lewis dot diagrams. My teacher wants it in the specific form where...
  33. M

    Use Rustum Roy's electrolysis method on other molecules?

    In reading the posts re:Rustum Roy and electrolysis on salt I wondered if that method would work on other molecules? Not thinking about energy in and out, just how that or other means to separate a molecule's atoms could solve some problems such as pollution? Also, use of the term 'burn'...
  34. Const@ntine

    Chemistry Measuring the Mass & Electric Charge of Molecules

    Homework Statement Hi! So I stumbled upon this simple "plug n' play" exercise in my Physics textbook. Basically it gives you certain molecules/atoms, and tells you to measure the Electric Charge, and its Mass. Pretty simple, but I hit upon some hickups. Anyway, let's get to it: Find the...
  35. D

    Water molecules effect on Hydrogen bonds in precipitation

    Cheers everyone. Can the amount of water molecules added to a solution impact the formation of a salt with its ions mainly bonded through hydrogen bonds with electrostatic like behaviour? Let me give Some background to the question first: I am studying the precipitation of Phosphorous(P) as...
  36. I

    Common name translation and transcription molecules?

    The molecules that replicate DNA are collectively called "replisome". Is there a similar term for all the molecules that synthesize proteins (both through translation and transcription)? Short of, of course, "protein synthesizers". I can't seem to find the term, any feedback appreciated!
  37. Pushoam

    Number of molecules moving in a given direction at a given speed

    Homework Statement I didn't get it. Consider velocity space. The no. of velocity vectors for a given speed is proportional to the surface area of a sphere of radius v in the velocity space. So, a fraction of velocity vectors with speed v in an elemental area dA is##\frac{ dA}A##. A = ##\Omega...
  38. Kuzon

    How do O2 molecules from solution get into ATP?

    This was a practice exam Q: ATP is added to the myosin ATPase domain in water labeled with an oxygen isotope. After 50% of the ATP has been hydrolyzed, the remaining ATP is isolated and found to contain 18O. Explain. I get how H2O is used in order to regenerate ATP from the Pi and ADP, but on...
  39. R

    What are the most common eigenstates of molecules in chemistry?

    What are the different eigenstates of molecules that are most often used in chemistry?
  40. G

    I Transition state of electrons in molecules

    Hi ! In my class we have an exercise that I technically understand but that I can't get conceptually. We have trois molecules (naphtalene, anthracene, tétracene). Considering each molecule as infinite quantum well of length 2L(naphtalene), 3L(anthracene) and 4L(tetracene), we would like to...
  41. Benoit

    Bonding and antibonding states of hybridized molecules

    Hey there, With covalent bonds, we have bonding and antibonding states. If we now have, let's say sp or sp2 states, doesn't matter, is there an equivalent bonding or antibonding state related to this sp bond ? I mean, why sp states wouldn't have antibonding states like every normal covalent bond ?
  42. R

    Chemistry Correct order of bond length in two organic molecules

    Homework Statement : [/B]The correct relation is: A. x=y B. x>y C. x<y D. None. Please refer to picture attached.Homework Equations : [/B]As stability increases, bond length decreases. When a Π bond is delocalised i.e it takes part in resonance, stability increases.The Attempt at a Solution I...
  43. I

    Order of molecules during transcription

    I wonder if this is a viable question: During transcription processes, which molecule in genes is "first in line", the phosphate group or the ribose sugar? I know they line up interchangeably, but does one of them "start" the process first? I guess I could ask the same thing about proteins...
  44. Konte

    Computing molecular symmetry group for non rigid molecules

    Hi everybody, My post today is about Molecular Symmetry group (MS) for non-rigid molecules. I read from this excellent work (Longuet-Higgins), that MS is obtained by selecting only feasible operation from Complete Nuclear Permutation Inversion Group (CNPI). My question is, As I have a quite...
  45. Konte

    Molecular symmetry group of non-rigid molecules

    Hello everybody, I have read some very interesting book (Molecular symmetry and Spectroscopy - Bunker and Jensen) that talk about how to find the Molecular Symmetry group (MS) of a molecule by using the concept of "feasible" operation from the Complete Nuclear Permutation Inversion (CNPI)...
  46. I

    How are angles in molecules calculated?

    I understand how angles are calculated in compounds where an atom is bonded to 2, 3, 5, and 6 bonds (bond pair + lone pair). But how do they work out the angle of a compound where an atom has 4 bonds (i.e. methane), in this case the carbon atom, has a H-C-H angle of 109.5°
  47. S

    I What is the significance of calculating the average value of cos?

    In kinetic theory, the number of molecules hitting a unit area of a surface per unit time with speeds between v and v + dv and angles between \theta and \theta + d \theta is found to be a function of sin(theta) and cos(theta). There will often be a practice problem asking to show that the...
  48. Ryaners

    Chemistry Calculating the number of water molecules in trans. metal complex

    Homework Statement [/B] I had an inorganic lab this week which involved making VO(acac)2 from VOSO4⋅xH2O. In order to calculate the percentage yield, I need to work out x, that is, the number of water molecules coordinated with the vanadyl sulfate n-hydrate before the reaction. I'm stuck...
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