Tungsten Definition and 49 Threads

Lets say that i have i mole of tungsten atoms. They are all ionized, only one electron is removed from each atom. If i accelerate this mole of tungsten atoms through one electron volt, i would get 96.48 kj. If the mole of tungsten was doubly ionized, two electrons removed from each atom, and...

I was taking notes from a lecture on Quantum Physics and during the introduction, they gave an example of what led to the discovery of Quantum Physics: The electric bulb example where the brightness and colour of light depended on the temperature of the filament(see...

Does anyone know if a tungsten-/copper+ saltwater battery have any significant charge if any? Willing to experiment myself, but don't want to waste money without asking first

Me again, with another potentially ignorant nuclear science question: Why isn't tungsten used to prevent meltdown in nuclear reactors? If tungsten has a higher melting point of tungsten is almost 6200 degrees Fahrenheit, and nuclear meltdown happens when the uranium fuel is some 5200 degrees...

Hello! Please tell me what Effective electron mass of tungsten and Effective hole mass of tungsten?

I was looking for any credible sources who could reveal the resistance of a normal tungsten filament bulb at room temp 20 C? I heard its cold resistance is about 9.5ohms. Is that the resistance at rtp? Thanks a lot in advance!

I was looking at this neat graph of all the isotopes and which ones are stable and how they decay: https://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Table_isotopes_en.svg/715px-Table_isotopes_en.svg.png The black squares represent stable isotopes, and columns that have no such black...

In my research group, I'm tasked with determining the purity of a tungsten sample sent from a supplier. Using FIB, we cut a 20 by 20 by 20 micron well into the sample and tested a wall of the well about 10 microns down from the surface. After taking a spectrogram, there seemed to be a large...

Good evening, So... I am looking for the Tungsten permettivity and i don't find this feature... I have searched on Wikipedia, some material data but i don't find... Do you know what is the Tungsten permettivity? Thanks.

Homework Statement Ina light bulb, billions of electrons flow through the tungsten wire bumping around, causing the filament to glow hot. Hot tungsten evaporates slowly, so its initial thickness profile r(x, t=0) can change over time. Consider a volume V of tungsten, with N bonds total, each...

Does anybody understand the fundamentals of what is happening in this circuit? Tungsten welding info is all about high current... but this is a low current scenario. AC input, CDI Coil generated 20Kv (estimated) suffers voltage drop over 100mm of tungsten rod. The larger the diameter... the...

In an Xray tube containing tungsten target , 50kV voltage is applied. Calculate the minimum wavelength of xray emitted. If the target is replaced by molybdenum will the min. wavelength change. Justify your answer? I used λ min= hc/eV= 2.481×10^ (-11) m for the 1st part. For the 2nd part I am...

With increased pressure tungsten has a higher melting point. (source below page 30) 45kBar increases melting point from 3422oC to 3700oC. http://www.nist.gov/data/PDFfiles/jpcrd55.pdf An ideal 5800 K black-body, truncated would be 37% efficient...

Hi guys I have been playing around with a piece of tungsten wire by supplying it with 12Vdc and measuring the current draw to see how much the resistance changes when the wire is glowing hot. while doing this i am not getting any change in the resistance, the wire has the same resistance when...

At the bottom of page 54 of Tungsten: Properties, Chemistry, Technology of the Elements, Alloys, and Chemical Compounds by Lassner and Schubert: I'm presuming the reaction goes something like 2H_{3}PO_{4} + 2W → 3H_{2} + 2WPO_{4} Since I'm pretty sure copper phosphate works just fine for...

How can I get Young's modulus value of Ferrous Tungsten? Is it possible to get it from Young's modulus value of Ferrous and Young's modulus value of Tungsten?

Homework Statement I want to know the Young's Modulus of Ferrous Tungsten. Homework Equations Is it possible to get the Young's modulus of ferrous Tungsten from Young's modulus of ferrous and Young's modulus of Tungsten? The Attempt at a Solution

Hi, For the purpose of my FYP I am carrying out temperature analysis on a single point cutting tool while machining on a lathe. I am using a handheld infrared camera to determine this. In order to carry this out accurately the emissivity of the material must be inputted to the device as a...

Homework Statement I'm doing a lab where I'm trying to find the emissivity of a tungsten filament. I measured voltage and current of a bulb with a tungsten filament and found the power. Then I plotted Power vs Temperature^4 and used the slope along with surface area and Boltzman's constant...

hey all. i am making a sample of bulk tungsten. but i am getting only about 84% denstiy... can anyone suggest a mathod of improving it? i do not want to change my sintering process so the method should be after i get the bulk... so... anyone can suggest a process to go from 84% bulk...

Hey guys, I'm quite a noob in physics. Okay, here's my idea: We use lead to protect us from gamma radiation because it's dense enough to somewhat absorb the tiny wavelenght. As I take it, tungsten is more dense than lead, right? Wouldn't it be safer to use tungsten instead of lead? (Looking...

Dear All I am trying to measure the spectrum of an incandesant 6V 15W tungsten microscope lamp. I have a reasonably old scanning monochromator (diffraction grating based) coupled to a fibre optic cable and it has given me the spectrum...

Also the chemical involve in the W and iodine. Thx

Homework Statement If we know, that 200 mm of tungsten wire weight`s 1.72 mg, then what is the diameter of this wire Homework Equations The Attempt at a Solution I by my self came to the conclusion, that the answer is 0.13 mm. But if I take in accordance, that my Algebra and...

How can I accurately control the Joule Heating effect of a length of Tungsten wire to certain temperature ranges? The tolerance would have to be no more than a maximum of +/- 2°C. Would I require alternating or direct current and/or any other associated instrumentation? I have little or...

I am looking to find the maximum psi or atm capacity of a tungsten tube of 99.9% tungsten. How would I do this?

I have been looking all over the web and can find nothing...How do I calculate this? Please help if you can..thankyou

Homework Statement How much positive and negative charge are in a 50g Tungsten ring? Homework Equations Standard atomic weight 183.84 The Attempt at a Solution

Homework Statement A K shell electron is ejected from a tungsten atom. The result of this is the emission of a characteristic x-ray proton. (The binding energy of the K shell in tungsten is 69.5keV. The binding energy of the L shell in a tungsten atoms is 10.5 keV). a) If the vacancy in the K...

Homework Statement Hello! I am supposed to explain the behaviour of the thermal conductivity of tungsten. I have plotted the relation http://img340.imageshack.us/img340/9776/heatcond.jpg is also experimental data Temp[0 10 50 100 300 500 1000 2000 3400] and thermal conductivity...

Hi ! Small doubts which need to be clarified. 1)What happens if tungsten is used in domestic wiring? 2)Fan has a regulator that is used to control and vary its rotational speed. Would it be possible to minimize the consumption of electricity by setting the regulator to the lowest speed?

Homework Statement the actual question is the resitivity of tungsten metal is 4.9x10to the power of -6 Ωcm. choose appropriate values for length and cross-sectional area for a home made wire resistor of resitstance 20Ω Homework Equations r=pl/a r-resistance a-cross sectional area in...

Tungsten Filament bending and production! my machine produces filaments for a UV lightbulb, the filaments are basically tungsten coiled tightly around a tungsten shank, and the machine used to do this perfectly! however it was switched off for a about a year during development. but now when...

Plotting a suitable graph to find emissivity of tungsten It is given that: Q = pσ2πal(T^4 - t^4) Where Q is the Energy Loss Rate, p is Emissivity and T,t are the wire and room temperature. Other symbols are constant. I have data for Q and (T^4- t^4), which for simplification purposes...

If i have a light bulb , and it has a tungsten filament and when i turn it on its gets hot , If i hook a lead to the filament and then put the anode away from the filament can i get electrons to flow through the vacuum , assuming this is done with DC current. If we used 2 different...

Does anyone have any expertise in the coating of WC tools? Are these tools coated by a deposition process (ex. CVD)?

Homework Statement Why is a tungsten filament used in incandescent bulbs? I earlier thought that it was due to the high resistivity of tungsten , but i was wrong , the resistivity of tungsten is low at 5.2 * 10^-8 Is it due to its high melting point?? I can't figure out as...

Hi, a friend of mine - a college physics professor, and me, have had a discussion about an experience he had in his early school days, and we haven't been able to prove or dissprove what he thinks he saw. During an incandescent light burn-out (12V bulb on 220V =), he thinks he might have...

Homework Statement 0.5 volts is maintained across a 1.5 meter tungsten wire that has a cross-sectional area of 0.6 mm2. What is the current in the wire? Homework Equations Resistivity of tungsten: 5.6E-8 ohm meters. Current Density: J = \sigma \cdot \frac{V}{l}, J = \frac{I}{A}...

]1. A 1.3 cm length of tungsten filament in a small lightbulb has a resistance of 0.032 ohms. Find its diameter. Given: Length= 1.3 cm= .013m R= 0.032 ohms resistivity= 5.6e-8 ohms*meter [b]2. A= pi (r^2) R= resistivity (Length/ Area) The Attempt at a Solution R= resistivity...

[b]1. A 1.3 cm length of tungsten filament in a small lightbulb has a resistance of 0.032 ohms. Find its diameter. Given: Length= 1.3 cm= .013m R= 0.032 ohms resistivity= 5.6e-8 ohms*meter [b]2. A= pi (r^2) R= resistivity (Length/ Area) The Attempt at a Solution R=...

Does anyone know of a combination type metal called tungsten zirconium nitrate or how to make it or the formula or msds thanks- The000agent

Hello, I have a Tungsten filament radiance source that has been calibrated in the UV region and would like to extrapolate the radiance to longer wavelengths. By calibrated, I mean, a NIST plot of spectral radiance v. wavelength at a certain set of operating conditions. I'm new to this...

Homework Statement Tungsten wire has an emissivity of 0.35. A tungsten filament in a light bulb can be considered to emit light only from the sides of the filament (consider it a cylinder... they are usually wire "cylinders" wrapped into coils.). If the operating temperature of the filament...

Homework Statement The K characteristic X-ray line for tungsten has a wavelength of 1.94 10-11 m. What is the difference in energy between the two energy levels that give rise to this line? Express this in each of the following units. (a) joules J (b) electron volts eV Homework...

So one of the big advantages to using depleted uranium (DU) rather than tungsten in anti-tank rounds is because a DU projectile will self sharpen upon impact whereas a tungsten projectile will flatten or "pancake". http://deploymentlink.osd.mil/du_library/how.shtml What is it about DU that...

Hello everyone I'm stuck on this problem it says: A common flashlight bulb is rated at 0.30 A and 2.9 V (the values of the current and voltage under operating conditions). If the resistance of the bulb filament at room temperature (20°C) is 1.4 , what is the temperature of the filament when the...

please check my work someone. A tungsten wire has a radius of .075mm and is heated from 20.0 to 1320 degrees C. The temperature coefficient of resistivity is 4.5x10^-3 (C)^-1. When 120V is applied across the ends of the hot wire, a current os 1.5A is produced. How long is the wire? Neglect...

I'm looking for a jump start with this one. I'm having trouble getting started. The tungsten wires of all electric light bulbs are designed to glow at about the same temperature. This requires, as a first approximation, that the power per unit surface area of the filament be the same for...