homework from cesar serrano escudero

WHAT IS A CHEMICAL REACTION?

Well this is a simple explanation of what a chemical reaction is:
A chemical reaction is a proces in wich two chemical substances join together and react.The substances that react are called REACTANTS.What they make is called a product.
this is an invented example:1 plus 2 equals 3
so 1 and 2 are the reactants
and 3 is the product


NUCLEAR REACTIONS

I was very interested in the nuclear reaction but it was very dificult so i only wrote a little about it.
A nuclear reaction is when two nuclear particles collide to produce different products.
tomorow I will show you some photos and videos of reactions in the web today I can t

Cesar serrano escudero y8c

Diary of... a Y9 SCIENCE class - February 26th 2007

Hello guys,
Today we had to finish all the experiments reports we haven't done as Andy is collecting them on next class (Thursday); he had already said this and he has posted it on the web so... we don't have an excuse (not at least that he didn't told it to us or any of us were not here: ¡We all came today!).
We also have to finish the acids handout's exercises (all except for number two).
Bye.

Need a bit more revision?

If you're finding that you're a little behind or want to read a little more in an easy and fun way try CGP books which are a great way to revise.

You can also buy them second hand on Amazon by typing CGP in the link below.



Years 7-9 you will need Science KS3 for the course we are on.

Year 9 - Books due in Thursday

Like I said at the end of last term and as Javi mentioned I will be taking year 9 books in for marking. I will do this on Thursday, and the main focus as I mentioned is on the Experiment you were writing up in the last week as well as some questions you will be set this week.

Remember your book MUST be with me by Thursday or you will simply get zero.

Marking grades

I will give most calculation exercises a numerical mark and anyone achieving less than 50% will be asked to redo their work.

The same applies to tests, and if you get less than 50% in a test you will be asked to resit the test on the next days lunchbreak and get more than 60%.

With other homework or experiments I will give you a grade that consists of a quality mark from A to E, A being Excellent quality and E being unacceptably poor work.

If you get a poor quality grade there's no point complaining about it, just make your work better.

You will also get an effort grade which goes from 5 to 1 where 5 is a lot of effort and 1 shows that a lot more effort could have been made.

So an A5 is a superb grade and an E1 is very very poor.

Simple

Marking books

Just so you know about book marking.

When I ask for your books in that is the day I want them in. I have a responsiblity to mark your books occasionally, but you as pupils have the responsibility to get your books to me when I ask for them.

If you are not capable of getting your books at the time I request them you will be given zero automatically for not handing in work.

If I get a string of zeros you will be asked to come in over a convenient lunchbreak to make up all the work missed.

I will NOT chase you for work if it is not in on time. You will simply get zero.

I give you ample time in advance to know that your books will be in and you need to learn that deadlines are given for a reason. Failure to make deadlines in life and in school will always have consequences so learn now to save you trouble in future.

If you're away on the day that work is due in, be it through illness or any other reason, then it is YOUR responsibility to ensure that your book is with me on that day.

Also if your WHOLE proper name is not on the book you are very likely to get zero as well - it saves me having to give someone the wrong mark by mistake. So FULL NAMES on your books with class please. If you make my life easier I will make yours easier.

You have been warned.

Now THAT'S what I call a lesson

A big thank you to the boys and girls of year 10 and 8 and anyone I've forgotten who helped me tidy up my lab on Tuesday.

Here's a pic of us all just about to start eating those 4 pizzas that we got delivered by telepizza.

Yummy!

ANDY WE'RE ALMOST DONE WITH YOUR CLASSROOM!!!

andy, we are starting to see the end of michael's mess in your classroom! we'll still have to work on it, but the worst part is over...and what a wonderful luch we had. it will have to be repeated...

Diary of... a Y9 SCIENCE class - February 16th 2007

Hello,
Today we had to write up the report of the experiment we did yesterday (comparing the reactions of two metals - iron & magnesium). We talked a lot about the conclusion looking the periodic table and the elements' place in it. The last people did their project presentations to Andy, so all the class has already done it. The books will be collected to be corrected next mid-term (after ski-week).
Bye.

Magnesium explosion!

150207 Y8C

Hello lads,
today in Y8C's class we needed to finish our last experiments and some questions on the Science Framework book. Tomorrow we need to give in books!

Diary of... a Y9 SCIENCE class - February 15th 2007

Hello,
Today we did the same experiments that the year 8s did yesterday plus three more (Yes! We really did five experiments). Another exp. was to add sulphuric acid to magnesium, holding the gas given off with our finger and then letting it go out into the flame and POP! We did the same with powdered iron, and more or less, the same happened but at a different speed.
Finally (although we did it first but it was the best), Andy mixed magnesium powder with a substance he didn't want to tell us what it was so that we didn't do it ourselves because it is very dangerous inside an empty and opened up beer can. We took this out, and Andy added glicerine to the mixture, and some while after, it exploded with a very bright white flame. It was AMAZING!!!!! After several minutes it was still burning!
And he said that this explosion is quite not big compared to another we will do in some weeks from now. I can't wait to this the next one!
Well,
see you.

Burning for learning

Year 8 burnt a few materials to compare them

They started with magnesium strip



..and they compared the reaction with iron by burning iron filings.

Web team league

With a month gone since I set the website up and web teams in every class the current posting league looks like this:

1. Obviously I have posted more than any team out there on my own


2. 7J with the mighty Isabel who never misses a summary


3. 9P - Javi is notably holding the team up there


4. 8P - Hugo making sure to tag all his posts


5. Yr11 - a single post on transformers


6. ...and still trailing behind with no posts at all 7A and Year 10 with no posts at all

Come on year 10 what's going on! So much to say in class but you lose your tongues when it comes to saying something useful huh...

Don't forget to tag your posts teams so that I can track what class tops the league every now and again!

magnesium burning

Magnesium burning

120207 Y8C

Today lads,
we did many experiments. The first one was outside...
We needed to do an explosion mixing some elements and comnpounds. it was great, nobody died unfortunately.
The next ones was mixing hydrochloric acid with magnesium and with iron. In all these experiments, some fire came out. It was fantastic.
This class has been one of my best Science classes I've ever had before. Simply marvellously perfect!!

Diary of... a Y9 SCIENCE class - February 12th 2007

Hello guys,
today we really didn't do anything except for presenting our projects about SPACE to Andy and hanging them up, and some didn't even do this! Surely, in our next lesson we'll do something more interesting. Until then:
See you.

Extra Spanish lessons

I know that you lot don't need them but I have just found this great site with podcasts and Spanish lessons for beginners at Coffee Break Spanish. This is what I'll have on my ipod for the next few months!

Easier to remember website name!

You can now reach physics heaven by just typing in the following...

www.scienceheaven.com

Year 8 - books to be marked next week

Year 8 - I will be taking your books in for marking at the end of the last lesson of next week.

For 8C this means Friday's lesson, and for 8O this is Thursdays lesson. Don't let me forget.

I will be marking the exercises I set you this week/next week and the practical write-up that you will be doing this week. All the practicals you have done so far have been practice write-ups. If you need any help with writing up practicals drop by my lab any time.

Year 7 tests marked - moving to next topic

Year 7 tests showed good general understanding mainly but many of your longer answers (question 9) were far too short to get you the marks.

You'll get those back on Monday, we'll check books over and move onto chapter 7H - Solutions, so if you want to read up about them then feel free.

Y8C class

Today in science class we stuck the posters to the wall. We are making a giantic periodic table.


Andy wasn t in class today he went with the y9 to the space center. He sent us some work and of course we did it. Some of us didn t finish so we took it as homework.

By the way Andy how are you doing with the spanish classes.

A question

My father has ask me a question.What happens whith the wood when you burn it where has the wood went?

Y8C science class 090207

Today, Andy went to an excursion to the space center I think.
What we did was to do what Andy told us to do, which was to paste the poster on the great periodic table, on Andy's white wall.
Then we did the Science Question that we are suppossed to do.

Pics from todays space centre trip

All the other pics I uploaded are now on the school computers. Here are the ones without faces...



Hope you all had a great time!

Where you can buy books if you've lost your own

Next week I will be checking on books so make sure you bring YOUR OWN textbook to every lesson (which you should be doing anyway).

Remember that it is YOUR responsibility to look after your own books. If you do not have the book you were issued with at the end of the year you will be charged for it.

If however you have lost your book, don't despair.

You can still buy yourself a new one (which will be handed in at the end of the year in place of the one that has been lost) by clicking the links below and asking your parents to get it sent over. This is the quickest, cheapest and by far the easiest way to replace missing books.

Year 7
Framework Science: Students' Book Year 7

Year 8
Framework Science: Student's Book Yr.8 (Framework Science)

Year 9
Framework Science: Student's Book Year 9

Year 10 and 11
Complete Physics

Diary of... a Y9 SCIENCE class - february 8th 2007

Hello,
Today we started doing the presentations we started to prepare on the last class, well, we also had some time to prepare them more today also. Then we talked about the projects (which are due on Monday) and Andy solved all the doubts about it. Then we decided to go to the ICT room to get some information about the project but there was a class. So we went downstairs to the library instead.
¡Remember: tomorrow we have the excursion to the SPACE CENTRE!
Note: the ones who didn't have the permission slips for the trip today, remember to bring them tomorrow or... you will not go.
See you.

080207 y8c

HELLO PEOPLE,
TODAY WE WENT TO THE LIBRARY TO LOOK UP FOR INFORMATION ABOUT OUR ELEMENTS.
LAST EXPERIMENT ON MONDAY WAS GREAT AND WAS AMAZING TOO.
WE MIXED UP CHALK PIECES WITH HYDROCHLORIC ACID.
IT WAS TREMENDOUSLY FANTASTIC.
I PUT PINK CHALK ON MY TEST TUBE AND SOME PINK BUBBLES STARTED TO COME OUT OF THE TEST TUBE!!!

year 8c class on monday

in monday s class we where investigating acids.We learned that all acids

1Are liquids
2Have reactiva hydrogen particles in them
3React to form SALTS


we also learned about ELEMENTS AND COMPOUNDS
Elements contain particles or elements of only one type.Compounds contain atoms of two or more elements chemically joined together.to separate a compound into it s elements you have to carry out a chemical reaction.

Essay Reminder: Borja Zubiaga

This is a message for Borja Zubiaga in year 10.

I notice that you have forgotten your sheet of paper with your essay title in your book today. That's the essay that I set you in class for talking over me.

Now before you try to use this as an excuse to NOT hand me in your essay by 9am tomorrow, remember that it is NOT an excuse for these reasons:

1 - I didn't ask you to write the essay in your book I asked you to write it on paper so handing in your book is not a valid excuse

2 - If you've forgotten the title it is HERE:

"The Grammatical structure of the past tense in Spanish"

And in case you've forgotten what it's for, it's 1 side for talking over me and 1 side for arguing with me.

Due 9am tomorrow in my classroom.

If it's not in by 9am tomorrow, you will be in with me for the whole of lunch completing 3 sides on the same subject.

Don't forget, 10 words per line, and a random count will be done to ensure that no line contains less than 10 words. If it does you do the whole essay again.

Oh and as further incentive, if your essay is not in by 9am (or 3 sides by the end of lunch) it's 4 sides the next day and I ring your mother too.

Enjoy!

P.S. If anyone has his number give him a call please to make sure he doesn't end up trying to use this as an excuse. Thanks!

Andy

Math multiplication

Look at this Video of multiplications with only lines.It works!

Web teams: Added to web area of the forum

Anyone who is a confirmed member of the web teams and is writing for this site now has exclusive access to the web teams area of the forum.

In here you can discuss any areas that you think can be improved with regards to the design and use of the web for learning science.

You will notice when you log in to the forum that you have a "web teams" area in the bottom of the forum, which no-one else has access to.

Good work Hugo on the new banner at the top of this site!

Web team members - joining the web team - deadline

I have sent out the invites one final time to those of your who submitted requests to join the web teams for your class.

You should have an email from phoenix in your inbox. You need to click through the link and join up.

At the moment 29 of you have still not joined despite putting your names up to join the web teams. We already have 24 webwriters so if you don´t join by the end of the week I will take delete your invitation and you are no longer qualified to be part of the web teams.

This is the final time I will send these invitations out.

New pics and vids added in school

This link cunningly only works in the school computers.

Copy and paste the following into your browser address line for the latest pics and videos of your science classes.

My Network Places\\Npc10\shareddocs\Science Photos and Videos from Andys class\

(I haven´t figured out how to make it work directly by clicking yet - Hugo?)

Web teams, remember you can take pics and vids and put them in this folder yourself, as they are only on the school network, so faces etc are allowed. As usual, for anything on this site though, as it is external and anyone can see it, usual rules apply as you know.

Some pics from class

Chalk reaction with acid using coloured chalk



Lime Water - for testing carbon dioxide



Using Lime water and a delivery tube to test for CO2

Classic Engineering Disaster: THe Tacoma Narrows Bridge collapse

The last post I put up was about a chemistry-related disaster: Here's a physics/engineering related disaster, and a good reason why you need to make sure that you do your calculations correctly!

At a mile long, the Tacoma Narrows bridge was the third longest bridge in the world at the time it was built.

The first version of the bridge, nicknamed Galloping Gertie, was designed by Clark Eldridge and altered by Leon Moisseiff. In 1940, it became famous for a dramatic wind-induced structural collapse, an event that was caught on motion picture film. The replacement bridge opened in 1950.

The guy who designed this first bridge asked for $11 million but only recieved $6 million so he had to cut a few corners. And in the video that you're about to see you can see what happens when you do that (physics is not only about getting the questions right in the exam - if you get them wrong in real life then THIS could happen. Seriously.)



The wind-induced collapse occurred on November 7, 1940, due to a physical phenomenon known as mechanical resonance. From the account of Leonard Coatsworth, a driver stranded on the bridge during this event:

" Just as I drove past the towers, the bridge began to sway violently from side to side. Before I realized it, the tilt became so violent that I lost control of the car… I jammed on the brakes and got out, only to be thrown onto my face against the curb… Around me I could hear concrete cracking… The car itself began to slide from side to side of the roadway.

On hands and knees most of the time, I crawled 500 yards [450 m] or more to the towers… My breath was coming in gasps; my knees were raw and bleeding, my hands bruised and swollen from gripping the concrete curb… Toward the last, I risked rising to my feet and running a few yards at a time… Safely back at the toll plaza, I saw the bridge in its final collapse and saw my car plunge into the Narrows. "

The final destruction of the bridge was recorded on film by Barney Elliott, owner of a local camera shop. The Tacoma Narrows Bridge Collapse (1940) is preserved in the U.S. National Film Registry, and is still shown to engineering, architecture, and physics students as a cautionary tale.

No human life was lost in the collapse of the bridge. Theodore von Karman reported that the State of Washington was unable to collect on one of the insurance policies for the bridge, because its insurance agent fraudulently pocketed the insurance premiums. The agent, Hallett R. French who represented the Merchant's Fire Assurance Company, was charged with grand larceny for withholding the premiums for $800,000 worth of insurance. The bridge, however, was insured by many other policies that covered 80% of the $5.2–million structure's value. Most of these were collected without incident

On November 28, 1940, the U. S. Navy's Hydrographic Office reported that the remains of the bridge were located at geographical coordinates 47°16′00″N, 122°33′00″W, at a depth of 180 feet (55 m).

More on the Tacoma Narrows collapse can be found on Wikipedia

The Hinderberg Disaster

The following video is real footage of the disaster that Santiago mentioned in his earlier post

The Hindenberg was a very efficient airship invented by the Germans in the 1930s.

Along with its sister-ship LZ 130 Graf Zeppelin II, it was the largest aircraft ever built. It was 245 m long (804 ft) and 41 m in diameter (135 ft), longer than three Boeing 747s placed end to end and 78 feet (23.8m) shorter than the Titanic.

The Hindenburg was originally intended to be filled with helium, but a United States military embargo on helium led the Germans to modify the design of the ship to use flammable hydrogen as the lift gas.

As Santiago mentions in his post, Hydrogen is a HIGHLY flammable gas, so this modification was ultimately to prove fatal.

Germany had much scientific and technical experience with hydrogen, and hydrogen-related fire accidents had never occurred on civil zeppelins, therefore, the switch from helium to hydrogen did not cause much alarm. It also gave the craft about 8% more lift capacity. Knowing the risks of hydrogen gas, the engineers used various safety measures, including treating the airship's coating to prevent electric sparks. Such was their confidence that the airship carried a smoking room, pressurized to keep hydrogen out.

Harold Dick reported in his first hand account of his experiences as Goodyear Zeppelin representative during construction and operation of the Hindenburg, "The only entrance to the smoking room, which was pressurized to prevent the admission of any leaking hydrogen, was via the bar, which had a swiveling air-lock door, and all departing passengers were scrutinized by the bar steward to make sure they were not carrying out a lighted cigarette or pipe.

On May 6, 1937, while under tow to dock at the Lakehurst Naval Air Station in Manchester, New Jersey, the Hindenburg met its demise in a surprise flash fire that downed and destroyed the airship and killed 36 passengers, crew and ground crewmen. The incident goes down in the annals of history as one of the most devastating accidents to be witnessed in modern time. There has never been derived an absolute cause for the disaster, which has left history open to a number of unresolved theories.



More information can be found on Wikipedia or on the web about this disaster, and Akira, you may be interested in looking up the technical details of the Hindenberg and other Zepellins and putting them up on your airplane board

But for now pupils, sit back and witness for yourself one of the great explosions of the 20th century...

Digitally coloured version

class 6/2/2007

In todays class we had to do 2 presentations about various themes about space. We got 10 mins. to plan each one they were:

1. day and night
2. seasons
3. lunar eclipse
4. solar eclipse
5. phases of the moon
6. how satellites mantain in orbit
7. were the moon came from
8. story of the sun
   

Proyect about Hydrogen

Hydrogen

Hydrogen is a chemical element that has the symbol H and an atomic number of 1. At standard temperature and pressure it is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas (H2). With an atomic mass of 1.00794 g/mol, hydrogen is the lightest element.
Hydrogen is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass. Stars in the main sequence are mainly composed of hydrogen in its plasma state. Elemental hydrogen is relatively rare on Earth, and is industrially produced from hydrocarbons such as methane, after which most elemental hydrogen is used "captively" (meaning locally at the production site), with the largest markets about equally divided between fossil fuel upgrading.

History

Discovery of H2
Hydrogen gas, H2, was first artificially produced and formally described by T. Von Hohenheim (also known as Paracelsus, 1493–1541) via the mixing of metals with strong acids. He was unaware that the flammable gas produced by this chemical reaction was a new chemical element. In 1671, Robert Boyle rediscovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by identifying the gas from a metal-acid reaction as "inflammable air", and further finding that the gas produces water when burned. Cavendish had stumbled on hydrogen when experimenting with acids and mercury. Although he wrongly assumed that hydrogen was a liberated component of the mercury rather than the acid, he was still able to accurately describe several key properties of hydrogen. He is usually given credit for its discovery as an element. In 1783, Antoine Lavoisier gave the element the name of hydrogen when he (with Laplace) reproduced Cavendish's finding that water is produced when hydrogen is burned. Lavoisier's name for the gas won out.
One of the first uses of H2 was for balloons. The H2 was obtained by reacting sulphuric acid and metallic iron. Infamously, H2 was used in the Hindenburg airship that was destroyed in a midair fire.

Combustion


Hydrogen can combust rapidly in air. It burned rapidly in the Hindenburg disaster on May 6, 1937
Hydrogen gas is highly flammable and will burn at concentrations as low as 4% H2 in air. The enthalpy of combustion for hydrogen is –286 kJ/mol; it combusts according to the following balanced equation.
2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ
When mixed with oxygen across a wide range of proportions, hydrogen explodes upon ignition. Hydrogen burns violently in air. Pure hydrogen-oxygen flames are nearly invisible to the naked eye, as illustrated by the faintness of flame from the main Space Shuttle engines (as opposed to the easily visible flames from the shuttle boosters). Thus it is difficult to visually detect if a hydrogen leak is burning. The Hindenburg zeppelin flames seen in the adjacent picture are hydrogen flames colored with material from the covering skin of the zeppelin which contained carbon and pyrophoric aluminium powder. (Regardless of the cause of this fire, this was clearly primarily a hydrogen fire since skin of the Zeppelin alone would have taken many hours to burn). Another characteristic of hydrogen fires is that the flames tend to ascend rapidly with the gas in air, as illustrated by the Hindenberg flames, causing less damage than hydrocarbon fires. For example, two-thirds of the Hindenburg passengers survived that hydrogen fire, and many of the deaths which occurred were from falling or from gasoline burns.
H2 reacts directly with other oxidizing elements. A violent and spontaneous reaction can occur at room temperature with chlorine and fluorine, forming the corresponding hydrogen halides: hydrogen chloride and hydrogen fluoride

This is my work on Hydrogen

Mentos+coca-cola=explosion

When you drop the Mentos into the coca-cola, the gelatin and gum arabic from the dissolving candy break the surface tension. This disrupts the water mesh, so that it takes less work to expand and form new bubbles.

Diary of... a Y9 SCIENCE class - february 5th 2007

Hellos,
Today we started talking about the Earth and Space. Why did we change of topic suddenly? 'cause we are going this Friday to the SPACE CENTRE and we have to remember and revise what we did some years before. First, we did some presentations about Night and Day, the Seasons and Eclipses. Then we had to prepare another presentation about the Moon's Origin and Why does the moon stay in orbit?. But, we didn't have time to present them because Andy had to talk to us about the excursion (and its permission slips: ¡the photocopier has broken again!) and a project we have to do for next Monday about the Earth and Space.

Bye.

Did you know?

ph really means "power of hydrogen". This is used to measure acidity or alkalinity( I suppose you already know this part). There is two ways of calculating the ph of a substance:

1. With a complicated equation:

or

2. With universal indicators like: red cabbage, litmus paper, phenolphthalein, methyl orange, phenol red, bromothymol blue, and bromocresol purple.

Another example of universal indicator is the plant Hydrangea macrophylla, which flowers change of colour depending of the pH of the soil (acid soil=blue flowers, alkaline soil=pink flowers)

(All links go to Wikipedia)

See you!

Science Y9R

Hello,

Today in class we've been talking about how to made an experiment report. Andy told us that it need to have an aim, an apparatus, a method, some observations, an explanation and a conclusion. After we started to discuss what we were going to do in the excursion to the space centre and we brought up the subject about gravity. So we did an experiment about it and after we did another one in which we cooked an egg with burning alcohol. It was amazing!!!!!

Until next time,

Alejandro

Y8P Class

Today Andy Has told us how to do an Experiment Report of the last experiment. First we had to write the title and the aime. After that it comes the apparatux that you could do a list or a diagram. Finally the Observation that consist of tell what happened.

After that we tried to do an experiment but we run out of time so we couldn´t.

See you tomorrow in class with ANDY !!!!!

THE CARACTERISTICS OF GOLD

Atomic number
79
Atomic mass
196.9655 g.mol -1
Electronegativity ccording to Pauling
2.4
Density
19.3 g.cm-3 at 20°C
Melting point
1062 °C
Boiling point
2000 °C
Vanderwaals radius
0.144 nm
Ionic radius
0.137 nm (+1)
Isotopes
7
Electronic shell
[ Xe ] 4f14 5d10 6s1
Energy of first ionisation
888 kJ.mol -1
Energy of second ionisation
1974.6 kJ.mol -1
Standard potential
+1,68 V ( Au+/ Au )
Discovered
c.a. 3000 BC

Gold is metallic, with a yellow colour when in a mass, but when finely divided it may be black, ruby, or purple. It is the most malleable and ductile metal; 1 ounce (28 g) of gold can be beaten out to 300 square feet. It is a soft metal and is usually alloyed to give it more strength. It is a good conductor of heat and electricity, and is unaffected by air and most reagents. Gold is usually alloyed in jewellery to give it more strength, and the term carat describes the amount of gold present (24 carats is pure gold). It is estimated that all the gold in the world, so far refined, could be placed in a single cube 60 ft. on a side. The most common gold compounds are auric chloride (AuCl3) and chlorauric acid (HAuCl4). A mixture of one part nitric acid with three of hydrochloric acid is called aqua regia (because it dissolved gold, the King of Metals). It is unaffected by air and most reagents. Applications Gold is used as buillon and in jewellery, glass and electronics. Jewellery consumes around 75% of all gold produced. Gold for jewellery can be given a range of hues depending on the metal with which is alloyed (white, red, blue, green etc.). Colloidal gold is added to glass to colour it red or purple, and metallic gold is applied as a thin film on the windows of large building to reflect the heat of the Sun's ray. Gold electroplating is used to in the electronic industry to protect their copper components and improve their solderability. Gold in the environment Glod is widely distributes on the earth at a background level of 0.03 g/1000 kg (0.03 ppm by weight). Its interness and its high density causes it to concentrate in streambeds, either in small flakes or in larger nuggets, from which it may be recovered by panning. It is found free in nature and associated with quartz, pyrite and other minerals. Most gold is mined and comes from gravels and quarts veins or is associated with pyrites deposits. Two thirds of the world's supply comes from South Africa, and 2/3 of USA production is from South Dakota and Nevada. Other main mining areas are Canada and Russia. Gold is found in sea water, but no effective economic process has been designed (yet) to extract it from this source. World production is around 2500 tonnes per year, but reserves are estimated to be ten of thousand of tonnes. Health effects of gold Effects of exposure: Inhalation: May cause irritation if exposure is prolonged or excessive. Ingestion: No adverse effects expected. Skin: May cause irritation and allergic reaction. Eye: May cause irritation. Gold is used to cure rheumatoid arthritis, under a treatment called Chrysoteraphy. It is prescribed when treatment with non-steroid antu-infiammatory drugs is failing to give relief. Environmental effects of gold Gold has not been evaluated for its ecotoxicity. However, the biodegradation of gold under aerobic conditions is expected to be very poor and there is no evidence to suggest it creates ecological problems when released into the environment. Since gold is insoluble, it is believed to have minimal bioaccumulation and bioavailability characteristics

. Click here for more historical datBack to periodic chart. a on the price of gold
.

Diary of... a Y9 SCIENCE class - 1st February 2007

Hello,
Today we did an experiment which was very similar to the one the year 8's did, but our aim was different. We were looking at the reaction between acid and carbonates and one of its products: CO2 (Carbon Dioxide). We also put acid on chalk (calcium carbonate) and on egg shell (also calcium carbonate but crystalized) and we took the gas produce through a delivery tube to some limewater, which turned white because it reacted with it.
We also talked about safety in the lab, and Andy told a disgusting experience which, I'm sure you don't want it to happen to you. So: ALWAYS BE SAFE!!

See you tomorrow