Grafeno.

~¿Qué es el grafeno?

Es una alitropía del carbono (carbono con otra estructura) concretamente presenta una estructura de teselado hexagonal plano (como la forma de los panales de abejas) que, además, esta formado por carbono y enlaces covalentes de carbonos enlazados.

El grafeno forma el grafito (mina de los lapices) cuando se coloca en capas superpuestas.

~¿Cuáles son sus principales características?

• Autoenfriamiento.
• Alta conductividad térmica y electrica.
• Alta elasticidad y dureza.
• Resistencia.
• Soporta la radiación ionizante.
• Muy ligero.
• Se calienta poco al conducir los electrones.
• Consume poca electricidad.
• Genera electricidad al ser alcanzado por la luz.

~¿Qué aplicaciones se te ocurren?

Se podrían realizar novedosos aparatos eléctricos los cuales no necesiten ser cargados, ya que el grafeno generaría electricidad al exponerse a la luz. Más que nada pienso que serviría para circuitos, aparatos electrónicos, etc.

Marco Polo

• Who was Marco Polo? (You can research this online)

He was a Venetian merchant traveler. He learned about trading whilst his father and uncle, travelled through Asia and apparently met Kublai Khan. In 1269, they returned to Venice to meet Marco for the first time. The three of them embarked on an epic journey to Asia, returning after 24 years to find Venice at war with Genoa; Marco was imprisoned, and dictated his stories to a cellmate. He was released in 1299, became a wealthy merchant, married and had 3 children. He died in 1324, and was buried in San Lorenzo.

• What historical period is the text from? What do you know about this period?

The text is from the Middle Age. In this period, in Europe, the people were very poor except the kings and the nobles. The Cristianism controled Europe. But in Asia there were a lots of new advances.

• What region does the text discuss? What do we call it nowadays?

It discuss about Catai. Now called China.

• Compare the technological developement of the East with that of the West during this period.

In this period in the East there are invents about the agriculture because, in the land of the science the people couldn't investigate because the Cristianism didn't leave them. But in the East they were not of this religion, they were islamic and jewish so they could investigate the anatomy and other things so their invents were better then the invents of the West.

• Why do you think the book was giving this title?

Because he didn't know all the things that he discovered in this place and he thought that they were magical

• What stones do you think the text is talking about?

The text is talking about the coal.

• What properties and advantages do the stones in the text have?

The properties were that the stones were black and they burned for a long time with a constant heat.

• Was there an equivalent to these stones in the West?

The wood.

• Do you think the use of these stones in the West triggered technological advances? Which ones? Why?

Yes, they could invent the things that need a lot of heat, for example the bathes. Because the had these stones. 

Ejercicio 9

Ejercicio 8

Ejercicio 7

Ejercicio 6

Ejercicio 5