Helium Definition and 389 Threads

  1. B

    Is filling a football with helium really beneficial for hang time?

    Hey guys, in an article it states: Why is this true? What other info can I obtain from this/what info is missing/what is (in)accurate? From what I can think of myself. The reason of why this would happen is that since helium is lighter, the force the helium particles are exerting on...
  2. M

    Investigating Helium Ion's Wavelength Transition

    here is the question I am stuck on: Radiation from a helium ion He+ is nearly equal to the wavelength to the H_\alpha line (the first line of the Balmer series). (a) Between what states (values of n) does the transition in the helium ion occur? (b) is the wavelenght greater or smaller than that...
  3. X

    Supercritical Helium: Does PV=nRT Apply?

    How closely, if at all, does helium in the supercritical phase obey PV=nRT?
  4. E

    How Many Balloons Can a Helium Tank Fill?

    A tank having a volume of .100 m^3 contains helium gas at 150 atm. How many ballons can the tank blow up if each filled balloon is a sphere of .300 m in diameter at an absolute pressure of 1.2 atm? Here is what I have so far: Assuming no gas is lost to the atmosphere, n is constant. R is...
  5. E

    Increasing G during the formation of helium.

    A hypothetical question: Say that Newton's constant G is increased a bit during the period between weak interaction decoupling and the time when photodisintegration becomes ineffective, and the helium is formed. (I.e. during the period when neutrons just decay). Would that give a larger or...
  6. J

    Calculating the Electric Potential Difference of a Helium Balloon

    I'm learning about charge right now and I have no idea how to start this one.. any help is appreciated. A helium balloon has a charge of q = 5.5 x 10^-8. It rises vertically into the air. d = 600m. from the surface of the Earth to final position A. The electric field that normally exists in...
  7. D

    How Does Helium-3 Energy Output Compare to Traditional Explosives?

    I am giving a presentation on helium 3 for a future energy source and i am looking for a way to describe (and compare) how much energy is released in a helium 3 reaction (D-T would be fine). some thing that would be clear to people who have no science background. (i.e. the amount of H-3 that...
  8. S

    How Can Helium Balloons Help in an Egg Drop Project?

    yes this is an egg drop project once again, i had the idea to use helium balloons, but the problem is that the whole thing must fit in a grocery bag. only two balloons fit in a grocery bag! that can't carry very much! we can't use paracutes, otherwise we can do anything. i tried just now to cut...
  9. B

    Absolute Zero : What keeps Helium from becoming solid?

    I'm guessing this most likely has something some to do with Helium's superfluidity, but I'm still managing to draw a blank on what exactly stops it solidifying. Any thoughts?
  10. S

    Helium gas is compressed form 1 atm and 25 degree C

    Helium gas is compressed form 1 atm and 25 degree C to a pressure of 10atm adiabatically. the lowest temp. of helium after compression is i don't know how to start if anyone can give me hint to start the problem it would be a great things thank you waiting for your answer i got the...
  11. C

    Calculating Properties of Helium Gas Under Isothermal Compression

    a 2.00 mol sample of helium gas at 300K and 0.400atm pressure is compressed isothermally to 1.20atm Find the volume of the gas, work done on the gas and the energy transferred by heat just wondering how to approach this question, and what formulae i hould use where?
  12. C

    Helium Entropy at Absolute Zero: Exploring the Unknown

    Would the entropy of helium at absolute zero be zero?
  13. S

    Finding Heat Flow in a Brayton Cycle for Helium

    The question gives a picture of a brayton cycle with temperature on the x-axis and pressure on the y-axis. It is for the monatomic gas, helium, and we are told that there are two moles. The diagram consists of two adiabatic processes and two isobaris processes. You are given two temparatures...
  14. P

    Argon vs. Helium for Window Insulation: Which is Better?

    We have to to a report in our chemisty class on heating houses. One aspect is the window. Our teacher says that good windows are filled with argon becuase they have a high specific heat. but looking on the internet I seem to find the specific heat of argon to be about 520 J/kgC which is...
  15. L

    Calculating Density of Helium Gas at Different Temperatures

    The density of helium gas at 0.0 degrees C is 0.179 kg/m^3. The temperature is then raised to 100.0 degrees C, but the pressure remains constant. Assuming that helium is an ideal gas, calculate the new density of the gas. Ok, so far i figure that since P is constant, I would need to work...
  16. P

    Hydrogen to Helium Helium to heavier elements

    Would someone mind (in simple terms if possible) explaining how at the beginning of the universe Hydrogen combined to give Helium; then then how Helium combined with deuterium to create the heavier elements? I would just like to be more versed on this process... Thanks for any help!
  17. D

    Gravity and Helium: Why Does Helium Float Up?

    If gravity aplies the same force on every object, accellerating it to about 10 m/s2 (gee), then how come for example helium floats up to the sky? Thnx
  18. H

    Archimede's law and helium help

    Suppose I knew the densities of air and helium and I make a helium balloon. If I know the lift (in Newtons), how can I find the volume of the balloon?
  19. Gokul43201

    How Does Helium's Dielectric Constant Vary with Temperature?

    I'm having trouble finding reliable data on the dielectric constant of helium(4) gas as a function of temperature, from 4K up. Grateful for any help
  20. A

    Fusion Reactors & Moon Helium: Is Helium a Better Option?

    Is helium a better alternative then the current proposed fuels for fusion reactors? http://www.space.com/scienceastronomy/helium3_000630.html http://www.asi.org/adb/02/09/he3-intro.html
  21. D

    Helium Balloon Motion in a Moving Car

    how come when a car accelerates w/ a helium balloon, the balloon goes forward?
  22. Y

    Energy required to ionize helium

    Hi, It requires 79.0 eV to remove both electrons from He in the ground state. The energy to remove a single electron is 24.6 eV. What is the relationship between these two numbers? Thanks.
  23. R

    Does Superfluid Helium Behave as a Single Particle with Unified Spin?

    In a superfluid a small volume of liquid can be considered to behave as a single particle.Does this mean that ,for example,one cm^3 of helium-4 atoms has a total spin of 2?
  24. R

    Helium balloon in zero gravity

    a couple nights ago whilst my presleep thoughts wondered about, i came across a balloon filled with helium. in this thought, i saw the not uncommon sight of it floating up. then i wondered why it went up and not down or some arbitrary direction. i know helium is lighter than our oxygenic...
  25. S

    How can we study the composition of the Sun and Jupiter without direct samples?

    Stuck again with this "not so informational" astronomy book, and we need help with a question. What produced the helium in the Suns atmosphere, Jupiters atmosphere, and the suns core? :cry: can anyone help us?
  26. Mk

    How much does liquid helium cost

    No, I'm not thinking of buying one/any, but how much does one cost?, any type. Plus, how much do the two commonmost types of helium in liquid form, and/or liquid nitrogen, cost per gallon? I know liquid nitrogen is cheaper... a lot. ...If I were to not buy in bulk.
  27. T

    Rms speeds at 20 degrees celcius of atoms of helium

    1. Calculate the rms speeds at 20 degrees celcius of atoms of helium (4u)? 2. The escapte speed from the surface of the Earth is 11.2 km/s. Find at what temp. the following gas (O2) have this value as the rms speed? 3. One mole of an ideal monatomic gas is heated from 0 degrees celcius...
  28. maverick280857

    Wave Equation for the Helium Atom/No of terms = 2 or 3?

    Hi friends... Sometime back, I encountered the Self Consistent Field Method in Quantum Mechanics, which is used to compute wave functions in complex atoms. The book I read this from is "Practical Inorganic Chemistry" by Clyde and Day. The method is explained through an argument about the...
  29. X

    Solving Ideal Gas Law: Find Final Volume of Helium

    Given: R=8.31451 J/(K*mol) Two moles of helium gas initially at 187 K and 0.33 atm are compressed isothermally to 0.57 atm. Find the final volume of the gas. Assume the helium to behave as an ideal gas. Answer in units of m^3. I've tried this many many times and i keep getting 5.455...
  30. S

    Sir, i get the fllowing reply for my question 'can helium be

    sir, i get the fllowing reply for my question 'can helium be changed to hydrogen' '' Helium to Hydrogen requires energy input, for just the same reason that Hydrogen to Helium produces energy. The mass of four protons is greater than the mass of a Helium nucleus (alpha...
  31. S

    Is it possible to change the helium of the sun to hydrogen

    sir, I have to questions, 1. is it possible to change the helium of the sun to hydrogen. 2. can laser stop the electromagnetic wave if laser is charged to the electromagnetic wave face to face. soumya
  32. Nim

    Half-Life vs Electron Volts: Exploring Helium Isotopes

    I was looking at a http://chemlab.pc.maricopa.edu/periodic/isotopes.html and was wondering why the half-life was sometimes replaced with electron volts? There's an example from the table below: Helium-6 806.7 milliseconds -> Lithium-6 Helium-7 160 KEV -> Helium-6...
  33. N

    Calculating Helium Balloon Volume for 500 kg Payload

    I can't seem to figure this simple helium balloon problem out? I would really appreciate some help? Thanks! Estimate the volume of a helium-filled balloon at STP if it is to lift a payload of 500 kg. The density of air is 1.29 kg/cubic meter and helium has a density of .178 kg/cubic meter...
  34. J

    Island in the sky - helium launch platform

    This is a new launch plaform idea to assist Nasa in meeting it's extra-planetary goals. It seems that a large helium-supported platform in the upper atmosphere could save a lot of launch energy and pollution. The platform might be quite large, perhaps 0.5 to 2 km in diameter, and could be...
  35. Mk

    What does liquid helium look like?

    He I need a picture of liquid helium itself for my project on superconductors. I've looked all over but I can't find anything
  36. S

    What is the relationship between helium volume and exam questions?

    The two questions that were on my exam, to be honest, i didnt answer because I didnt understand it enough to do so. But I am willing to learn and be shown the way to a legit answer, so please don't immediately give me answers. The questions are like this: The density of air near the...
  37. M

    Helium Wave Functions: One or Two for Electrons? Evidence & Implications

    Does it matter if we use one wave function to describe both electrons of a helium atom, or we need to use one wave function for each? Is there any empirical evidence of the right way?
  38. K

    How to Calculate Moles of Helium in a Balloon Using the Ideal Gas Law

    I was wondering if any of you guys could solve this problem for me with complete solutions. I have been at it for a couple of hours and I am running out of pencil. I would really appreciate your help! Problem: A helium balloon is used to lift a load of 110 N. The weight of the balloon's...
  39. Loren Booda

    Exploring Helium Stars: Composition and Characteristics

    Are there stars primarily composed of helium?
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