Question

The core of earth is 2900 to 6376 kms in thickness. It is composed of ______________.
A. Copper and nickel
B. Iron and nickel
C. Gold and nickel
D. Silver and nickel

Answer 1

Hint: The internal make-up of the Earth has been discovered through the science of seismology. The earth was a ball of molten rock, as the planet cooled over time, the surface layer crusted over leaving molten rock beneath. The process of cooling has left the Earth in the state it is today.

Complete Answer: The Earth remains geologically active, the surface is under constant, gradual change. It has a relatively large satellite, the moon, which is more than one quarter the size of the Earth.

Study of Seismogram has revealed that the earth has a spherical core at its centre. The earth in its initial stage was a ball of molten rock, as the planet cooled over time, the surface layer crusted over leaving molten rock beneath. The process of cooling has left the Earth in the state it is today. The core of the earth is classified into two groups - inner core and outer core. A solid inner core, more than 5000 kilometres below the surface, is enveloped by a molten iron-nickel outer core. A layer of semi-molten rock of a viscous consistency ranging from 30 kilometres to almost 3000 kilometres in-depth, the uppermost part of the mantle is termed as the asthenosphere. The temperature of the inner core of the earth is really hot. It is estimated to range from 3000 and 5000 Kelvins, equal to 4,940 to 8,540 degrees Fahrenheit.

Thus, the correct answer is option (B).

Note: The planet earth is also sometimes referred to as Terra, after the Roman goddess of the Earth in keeping with a solar system named after characters from classical mythology. The inner core of the earth is almost the same size as the Moon, measuring 2440 kilometres across.