Gold Definition and 189 Threads

There are two doors - one has lots of gold. You want to get gold . There are two guards (one for each door). Both of them know behind which door gold is kept. One guard always says the truth while the other always lies. You do not know who says the truth or who lies. But the guards know who...

I saw some protoboards at fry that say "gold plated" on them. Can these contacts be soldered to? It doesn't seem like solder would be able to bond with gold plating, but if not, what good is the protoboard?

hi everyone; how can I put gold only on my microscale cantilever ? Merci :)

Homework Statement Estimate the transmission of light with \lambda=1\mu m that is transmitted through 20nm thick gold film at 77k where The DC conductivity: \sigma_{DC}=2*10^8 \Omega^{-1} m^{-1}) The carrier density: n=5.9*10^28 m^{-3}) and the plasmon frequency...

Homework Statement one ounce of gold (taken to be 28.35g) can be pulled or drawn into a monofilament wire that can be up to 50km in length true or false support your argument with some evidence Homework Equations atomic mass of gold ,Au= 196.96 avagardo's number=6.02x1023...

Hi all: I have a 200nm Au seed layer. and I am electroplating Cu on that using a solution. but the result is not good. The adhesion between the electroplated copper and gold seed layer is very poor and it easily peels off. 1-I wonder how can I increase the adhesion between them? 2-Does...

I'm sorry if this question has been posted before, but how much energy would it take for thallium to decay into gold? I know it would cost more to decay thallium into gold than the gold is actually worth, but I'm just curious.

Why is alchemy not real? Did anyone ever figure out how to change base metals into gold? What is the closest anyone has ever come to this? Assuming they haven't , why can't they do it?

I have heard that it is possible to make gold today, but it is radioactive. Is it possible to make gold or other non-radioactive chemical elements? We do find non-radioactive chemical elements in nature so why can't humans make them?

1. The predictions of Rutherford's scattering formula failed to correspond with experimental data when the energy of the incoming alpha particles exceeded 32MeV. This can be explained by the fact that the predictions of the formula apply when the only force involved is the electromagnetic force...

Homework Statement A miser sits alone in the middle of a frozen pond holding a bag of gold coins. He is unable to walk on the slippery ice. Explain how he could use the gold to rescue himself. Homework Equations Ft=change in p The Attempt at a Solution -i'm really not sure,but...

The theory I have read When you charge an electroscope with a negatively charged rod, electrons are repelled to the bottom of the electroscope and the gold leaf rises. Then when you shine light above the fundamental frequency on the top plate of the electroscope, electrons are liberated from...

Is this Wikipedia diagram of white gold alloy wrong? The contributing proportions of Cu, Au and Ag seem to add up to 150% for equal portions of each metal. This is from the Wikipedia article http://en.wikipedia.org/wiki/Colored_gold#White_gold"

Hi I was wondering why high end audio equipment is plated with gold when copper is obviously cheaper and has a lower resistivity. Anyone shed any light on this? Thanks Paul

Just like the experiment in high school using zinc powder and sodium hydroxide, is there a way to use real gold plating without having to melt real gold. Such as gold nitrate? Is gold nitrate rare, expensive or dangerous? Thanks!

any can answer this? that why J.J Thomson strike gold by alpha particles in his experiment by which he propose model for atomic structure?

Check out the great new stuff Greg has in feedback! I will add 10 GOOBF cards (Get Out Of Banning Free) to Greg's free gold membership offer. I'm printing up flyers for The Evo child, Spawn and their friends to post. They might not enter for the free membership, but they will put up...

Can anyone explain the experiment? i am having a big doubt in it.

I'm taking Physics this year. The problem is that the lectures are not going to be in English, my native tongue, and I'm not yet fluent in the language of instruction. I'm an international student and will be dealing with this my entire studies. The book the class is using is Fundamentals...

Dear all, I have a quite easy plan: W want to evaporate a gold circuit on a Brass plate. Between this copper and gold I need to make an isolating layer to prevent short-currents. i thought to make this layer of Silicon-oxide. Is the possible to evaporate and what source can I use this for...

Just found out I'm receiving some Gold Award for volunteering I did during my 4th year. You need to get 76+ hours for the Award and I had 250 hours baby! Sweeeeeeeeeeeeettttttttttttt! Sharing the joy! I thought I was only going to get a Bronze too. Hope this looks good on my resume...

What is the relative permittivity of gold at radio-frequencies or specifically around 15-20MHz?

Gold being a very good conductor should reflect almost all light incident on it and should be appearing white or at least gray. then why is it golden...? pls do reply a detailed answer

[b]1. potassium cyanide is added to a powder containg pure gold and rock and reacts with gold in the presence of oxygen to form potassium gold cyandie and potassium hydroxide. what is the balance equation? zinc is than added it reacts wwith potassium gold cyanide. what happens than? what...

I'm trying understand surface plasmon resonance in a gold film, and have decided that gold must have a refractive index of say 5-10ish in optical light. However I'm not sure and I think I might be on the wrong track. Also does negative refractive index have anything to do with surface plasmon...

Homework Statement Gold, which has a density of 19.32 g/cm3, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber. (a) If a sample of gold with a mass of 1.708 g, is pressed into a leaf of 6.811 μm thickness, what is the area (in m2) of the leaf? (b) If...

If I pay the money and get kicked off PF again, do I get my money back? Does a membership have shielding qualities? I'll pay the money if it means I can stick around. I won't post anything too controversial, but there are some mentors I might have to PM. Would a membership help me in anyway when...

Hi everybody, I need to deposit 50 nm of gold on a transparent oxide layer. I need that this oxide layer would have a refractive index of 2, at the wavelenght 1.5 micron (infrared). I first tried with SiO2 but as many of you know the adhesion is very poor. Then I tried with ZrO2 and it...

Homework Statement An alpha particle (a helium nucleus, containing 2 protons and 2 neutrons) starts out with kinetic energy of 9.5 MeV (9.5106 eV), and heads in the +x direction straight toward a gold nucleus (containing 79 protons and 118 neutrons). The particles are initially far apart...

1. Homework Statement The alpha particles used by Rutherford had a kinetic energy of 7.7 MeV and, for a head-on collision would get to within a distance of 3×10-14m of the centre of the gold nucleus. However the actual radius of a gold nucleus is approximately 7×10-15m. 2. Homework Equations...

Homework Statement You somehow manage to get a gold ring with inner diameter 2.26 cm stuck on your finger, even though your knuckle has a diameter of 2.3 cm. The temperature of the ring is 23 degrees C. To what temperature would you have to heat the ring in order to get it off your finger...

When identifying resistors by colour codes there is gold (5%) and silver (10%) for tolerence. Is there any other colours for tolerence like these?

At what temperature will it fizzle up an go poof?

$ 300 for a gold medal and no monetary compensation Something that I find interesting about the olympics is vast amount of stars that are absent ; in particular those that involve European players . Take one example - soccer - I watched the Euro 2008 with gusto , I was never quite the soccer...

You have 2 balls. Both are identical in size and mass, but one is made of gold and is hollow,the other is not hollow and made from titanium. Find out which is which ball, and let's say both are covered with a black paint that is anti reflective, heat/electricity insulator. You can't use any...

What frequency of light must be used to eject electrons from a gold surface with a maximum kinetic energy of 6.48×10(−19)J ? The work function of gold is 4.58 eV. f=

Homework Statement A positively charged alpha particle is fired, in a direct line, at a positively charged gold nucleus: o--> O o: alpha, O: golden nucleus. Because of their mutual repulsion, the alpha particle does not actually hit the nuleus: it comes to rest, for a...

Hello All, I have a sample which has been covered in a layer of iron and gold for protection. So, in order to work with the sample, we need to etch away the metallic layers. I hear there is a specific chemical recipe for chemically etching away iron and gold from a sample. If anyone can link...

I’ll try for the gold ring first and then come back to earth. Trying to find out the max forces to snap a pipe in-half (torsion problem) I have a 3”OD mechanical round tube with 1/4” wall its (ASTM-A 519) grade and 20ft long. At one end is welded a 14” long arm with a 3000psi cylinder(column...

Will gold be a valuable resource in the future? What kinds of technologies depend on gold, and is there enough demand for gold in areas other than jewelry? Gold is always safe right, as an investment. When paper money loses it's value, gold won't right? Is that what is beginning to happen...

Can some one tell me the speciality of gold for being used in gold leaf electrocscope in spite of being expensive when there are so many cheper metals that fit the bill as it appears to me?

Homework Statement This problem is giving me trouble on many levels. Gold III hydroxide is used for electroplating gold onto other metals. It can be made from the reaction of KAuCl4 (aq) with sodium carbonate and water. a. Write a balanced equation for this reaction. b. To prepare a...

Is in old puters? i have read about a company that re claims gold from them and other electronic components.

Gold has atomic number of 79 whereas Lead has 82 but lead has 11.000kg/m3 density as to Gold's 19.000kg/m3. How come??

A rock hound finds a solid rock that contains only quartz and gold. The rock has a mass of 12.08 kg and a volume of 3.909×10-3 m^3. What is the mass of the gold contained in the rock? Density of gold: 19300 kg/m^3 Density of quarts: 2660 kg/m^3

Hi. First time asking question here so sorry if format is wrong. Question: Gold leaf, which is used for many decorative purposes is made by hammering pure gold into very thin sheets. Assuming that a sheet of gold leaf is 1.27x10^-5 cm thick, how many square meters of gold leaf could be...

A gold crown hangs from a spring scale reading it's mass as 14.7 Kg. When the crown is submerged in water while still hanging from the spring scale, it's mass now reads 13.4 kg. Knowing that its either all gold, or a gold and copper compound, figure out which of the two it is. If it is a gold...

Is it gold? Question, help needed :) A gold crown hangs from a spring scale reading it's mass as 14.7 Kg. When the crown is submerged in water while still hanging from the spring scale, it's mass now reads 13.4 kg. Knowing that its either all gold, or a gold and copper compound, figure out...

Homework Statement Determine the height of a 91 lbs. gold cube. Homework Equations I'm not really sure which equations are relevant here... this is an Honors Physics problem for my girlfriend, but she asked me to attempt and I'm in Physics. Anyways, I thought of and only found a few I...

Homework Statement Gold, which has a density of 19.32 g/cm^3, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber. (a) If a sample of gold, witha mass of 27.63g, is pressed into a leaf 1.000 µm thickness, what is the area of the leaf? (b) If, instead...