Metals are very useful and are often used, because they have special properties. Some of them are even called noble metals. But in some cases they can be unpleasant, for instance, there is no warmth in them. Wood, on the other hand, is much more pleasant to touch or to sit upon. Can you find some more advantages or disadvantages of metals?Teacher
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Metals can be also very reactive, such as sodium, lithium or calcium. They can be also magnetic, such as iron or steal. Each metal has some of it's own properties also. Some metals are better for something and others are better for something else, so I can't say that all metals got same dissadvantages or advantages. Something that can be dissadvantage in one thing can also be advantage in other, so I say there are no general advantages or dissadvantages. I will give an example. Buildings have some iron in themself to harden them. Aluminium cannot be used for that, beacause it don't have enought hardiness. But can you use steal foil instead of aluminium foil? I guess not, beacause it's too hard to curve. I hope you can see that something that can be dissadvantage, can also be advantage in other things.
I would say, from the point of view of a woman, that gold and silver have the advantage of looking nice because of their shine and metallic luster. Gold also stays nice over a longer period, silver, on the other hand, gets dark because of oxidation. This is already one of the disadvantages, another being the high price of both of the metals. This makes jewelry less attractive.
I also know that from the point of view of an electrical engineer both, silver as well as gold, are very good conductors of electricity, but are not used very often for the reason mentioned before - price.
Metals are often extracted from the Earth by means of mining, resulting that they are relatively rich sources of the requisite elements. Mineral sources are generally divided into surface mines, which are mined by excavation using heavy equipment, and subsurface mines.
Once the ore is mined, the metals must be extracted, usually by chemical or electrolytic reduction.
Matjaž are you answering on the questions, or do you only copy paste some informations from other sites?
It's true that gold and silver are expensive metals and there is always difference in metals, but that doesn't mean that this are advantages or disadvantages in general way, but can be advantage in some things and disadvantage in others.
You can say, that silver get dark beacause of oxidation, but are you sure that this is only disadvantage? This oxidation may be even used in industy and that could make it advantage. I really don't think that we can look on things only from one angle of view. Someday people thougth, that mud left over when getting copper from ore is just useless, but it was sometimes worth even more then copper itself, beacause it contained some others expensive metals. So they thouth that mud was disadvantage, but now they know it's advantage.
I simply like your answers, Matej. This is the is real idea behind this kind of learning.
Matjaž, you could learn a lot if you'd really read all the questions and also the comments. But I am not even sure you will read this.
Teacher
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