Gold is a chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In a pure form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native) form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium and also as mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides).
Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in metallic substances, giving rise to the term acid test. Gold also dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute this is not a chemical reaction.
A relatively rare element, gold is a precious metal that has been used for coinage, jewelry, and other arts throughout recorded history. In the past, a gold standard was often implemented as a monetary policy, but gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard was abandoned for a fiat currency system after 1971.
A total of 197,576 tonnes of gold exists above ground, as of 2019. This is equal to a cube with each side measuring roughly 21.7 meters (71 ft). The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold's high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices (its chief industrial use). Gold is also used in infrared shielding, colored-glass production, gold leafing, and tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine. As of 2017, the world's largest gold producer by far was China with 440 tonnes per year.
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...
heat turn iron to gold if heated??
Can Iron(Fe) be changed to gold(Au) if heated to a high enough temperature?
My attempt
Question 2
No, iron cannot be changed to gold by heating it to a high enough the temperature. Increasing the metal's temperature has no effect on the state.
Smolin used a really interesting analogy for the big bounce transition here:
http://cosmicvariance.com/2007/07/02/against-bounces/#comment-294116
the idea is a phase transition of the geometry of space which resets it to low entropy---and it looks like Bojowald's recent paper supports the...
In Rutherford's scattering experiments, alpha particles (charge = +2e) were fired at a gold foil. Consider an alpha particle with an initial kinetic energy K heading directly for the nucleus of a gold atom (charge = +79e). The alpha particle will come to rest when all its initial kinetic energy...
Hi everybody
I know that concentrated sulfuric acid doesn't react gold. But I am puzzled because the oxidation potential of sulfure in concentrated H2SO4 is even higher than that of gold. Could anyone help me please.
Thanks
Homework Statement
an alpha particle (charge=+2.0e) is sent at high speed toward a gold nuclues Charge= +79e. What is the electrical force acting on the alpha particle when it is 2.0 times 10^ -14m away from the gold nucleus
Homework Equations
The Attempt at a Solution
its 91 N...
Rutherford's "Gold Leaf" experiment with Beta Radiation
The other day at school I was doing about Rutherford's gold leaf experiment which proved the structure of atoms. In the experiment alpha radiation was fired at a thin piece of gold, resulting in most of the radiation simply passing through...
"Generation" of gold, silver, copper elements
Since gold, and silver, and copper are all elements, I am a little confused - are they generated, or is there already only so much of each in the Earth, period?
I know I found some data on Wikipedia that indicated that the various elements can be...
Sooo, as this is my first time posting I thought I'd start off by saying hello to you all=)
Anyway, the problem is as follows:
Point defects in metals can cause additional electrical resistivity at low temperatures due to extra electron scattering which is proportional to the number of...
The gold nucleus has an atomic mass of 197 with 79 protons and 118N and 79 electrons.
The top quark has about the same mass, but no internal structure. It's just a particle with pure mass.
Why would a structure of pure mass and nothing internal decay?
I thought I understood this problem, but my answer is wrong.
"In a sample of 18-karat gold, 75 percent of the total mass is pure gold, while the rest is typically 16 percent silver and 9 percent copper. If the density of pure gold is 19.3 g/cm^3, while the densities of silver and copper are...
The average density of the material in intergalactic space is approximately 2.5 × 10^–27 kg/m^3. What is the volume of a gold sample, ρ = 19 300 kg/m^3, that has the same mass as 8.0 × 10^24/ m^3 of intergalactic space?
a. 1.0 × 10^–6 m^3
b. 2.0 × 10^–5 m^3
c. 5.0 × 10^–5 m^3...
Gold, which has a mass of 19.32g for each cubic centimeter of volume, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber.
a) If the sample of Gold, with a mass of 27.63 g is pressed into a leaf of 1.000 micrometer thickness, what is the area of the...
For anyone who watches the World Juniors, you know what I'm talking about.
Canada shuts out Russia 5-0!
It was an amazing game. Justin Hogge obviously played awesome, and I'm looking forward to see him as a Leaf goalie.
All around great team.
DRINK UP CANADA!
In “Rumpelstiltskin,” the miller’s daughter is spinning straw into gold on a spinning wheel that turns at a speed of 7.5 m/s, making one revolution every 0.50 s. How long is a strand of gold that makes one complete turn around the wheel?
I know I am supposed to be telling what I know, but...
I'm not chemist, but I know a bit about the elements. I have a rock book which tells about the different gems and rocks, under gold, it is you cannot scratch gold with your fingernail, but with a knife.
I recently bought a 90% gold (10% alloyed with other harder metals) gold lucky angel. When...
Gold mine in Argentina
There is a gold and silver mine in esquel (a poor town of argentina) which must be exploited at open air. Also there is a multinational corporation from USA who is interested in exploiting it, promisin work for 300 workers.
A group of esquel residents worried about...
In the electrolysis of Au3+ (aq) solution, gold is deposited. How much gold is deposited in 6 hours by a constant current of 0.540 A?
I know you need to find the moles of e- by using It/F. But I'm not sure where to go from there.
Any help would be great.
Thanks.
Some say pure gold oxidizes,but it takes thousands of years and even billions of years to completely oxidize on normal/room temperature i natural envirornments.
1.So,does pure gold in water(normal drinking and salt water) oxidize at least on molecular level i normal/room temperature?
Because...
Hi,
I'm trying to figure out how to dissolve metallic Au in solution, for an electroplating solution, without the use of Nitric Acid, Cyanides, or other chemicals which i cannot obtain.
I can obtain many more common (less suspicious and dangerous) chemicals, such as concentrated HCl, H2SO4...
The electron drift speed in a gold wire is 3.0 * 10^-4.
1. What is the current density in the wire?
2. What is the current if the wire diameter is 0.50 mm?
I am unsure of which equation to use.
Q = I delta t ??
Can someone help me out?
The electron drift speed in a gold wire is 3.0 * 10^-4.
1. What is the current density in the wire?
2. What is the current if the wire diameter is 0.50 mm?
I am unsure of which equation to use.
Q = I delta t ??
Can someone help me out?
I just need a little help with this question..how should I finish a problem like this?
In a sample of 18-karat gold, 75 percent of the total mass is pure gold, density_gold = 19.3 g/cm^3, while the rest is typically 16 percent silver density_silver = 10.5 g/cm^3 and 9 percent copper...
I'm sure I am missing something simple here but...
Suppose a 1.72 g nugget of pure gold has zero net charge. What would be its net charge after it has 1% of its electrons removed?
So i know that an electron is 9.109 x 10^-31 kg, and has a charge of -1.602 x 10^-19C. However, how do i know...
I have a question regarding fluids
A small sculpture made of gold (density of gold = 19280 kg/m^3) is believed to have a secret central cavity. The weight of the sculpture in air is 25.76 N. When submerged in water, the weight is 23.86 N. What is the volume of the secret cavity. (Density of...
anyone familiar with this? Rutherford (Ernest) had a famous experiment with the gold leaf and some radiactive source. Anyone want to calloborate? Becuz i m not so clear on wat that is
Goooooold!
Hey people! I need you opinnion:
I bought week ago 10,000 $canadian dollars(all my savings) worth of gold,small bars,
you know in case something bad happenes to the economy or Bush starts new war with Iran etc.Was that a good idea?or am I stupid idiot?
I have to tell you guys...
These are hilarious!
Here are the top nine comments made by NBC sports commentators during the [2004] Summer Olympics that they would like to take back
1. Weightlifting commentator: "This is Gregoriava from Bulgaria. I saw her snatch this morning during her warm up and it was amazing."...
could some kind person please clarify a long standing argument within my circle of friends.It goes like this .There is a bridge spanning a gorge that can take a maximum of 80 kilograms(sorry for those not used to kilos ), a person wieghing 78 kilos must transport three gold bars weighing one...
"sometimes a rainbow, baby, is better than a pile of gold"
song lyrics by the band Poison.
Would you rather be lucky or rich?
I personally would want to be lucky cos I am sick of being unlucky. Money is not too much of a matter for me, I've been poor before. but at least now i am...
Just read this month's Pop Sci, and the article on using gold nanospheres in cancer detection and treatment was pretty encouraging. Obviously, there are many steps between an encouraging new idea and a working treatment, but Halas and West have a three million dollar grant and are ready to go...
Do you think a gold standard economy is better?
This is why I think it is better
The following section is a series of revised quotes taken form a book called
The creature from Jekyll Island, by G. Edward Griffin.
THE MISLEADING THEORY OF QUANTITY
It often is argued...