In pairs ask and answer text-based questions

For example:

· What will occur if the temperature of the crystal rises above absolute zero?

· Can you explain what takes place in an atom when one electron frees itself from a covalent bond?

· Is the hole able to attract electrons?

· What can you say about the process of recombination?

· Can you say anything about the rate of recombination?

· And the total number of free electrons and holes is constant, isn’t it?

18. Divide into 2 groups. Group 1 translates Extract A and group 2 – Extract B of the text “Supernovae” with a dictionary in writing.

Extract A

A supernova (the plural is supernovae) is the explosion of a star. They are extremely important for understanding our Galaxy. They heat up the interstellar medium, distribute heavy elements throughout the Galaxy, and accelerate cosmic rays. But what causes a star to explode? And is there more than one type of supernova? Indeed, there seems to be two distinct types of supernovae – those which occur for a single massive star and those which occur because of mass transfer onto a white dwarf in a binary system. As you will see, however, it is only what gets the process started toward the explosion which differs between the two types.

Stars which are 8 times or more massive than our Sun end their lives in a most spectacular way; they go supernova. A supernova explosion occurs when there is no longer enough fuel for the fusion process in the core of the star to create an outward pressure which combats the inward gravitational pull of the star's great mass. First, the star swells into a red supergiant...at least on the outside. On the inside, the core yields to gravity and begins shrinking. As it shrinks, it grows hotter and denser. A new series of nuclear reactions begin to occur, temporarily halting the collapse of the core. But alas, it is only temporary.