Английский язык. Ч.3 (Units 9,10). Ильичева Н.А - 21 стр.

   b) Read the text quickly and match the words in bold with their Russian
      equivalents:
1) ����������, ��������� �� ������������ ������;              6) ������������;
2) ���������;                                         7) �����������, �������;
3) ��������������;                                    8) ���� ������;
4) �����������;                                       9) ��������, ��������;
5) ������������, ��������;                           10) ����������, �������.
   c) Read the text carefully and do the following:
      1) state Planck’s hypothesis, and explain why it was so radical;
      2) explain what is meant by the dual nature of light;
      3) describe the photoelectric effect and explain the quantum theory that
         describes it.


   In the latter part of the nineteenth century light was shown to be an
electromagnetic wave. However, the theory had some rough edges because of
the discrepancies which were observed when the temperature of an
incandescent solid such as the filament of a light bulb was increased and a hot
solid went from a dull red to a bluish white. According to classical wave theory,
the intensity of the emitted radiation was expected to be much greater than was
actually observed. Actually it had to be proportional to the square of the
frequency. This discrepancy was termed the ultraviolet catastrophe:
“ultraviolet” because the difficulty occurred at high frequencies beyond the
violet end of the visible spectrum, and “catastrophe” because the energy
observed was much less than it was predicted.
   The dilemma was resolved in 1900 by German physicist Max Planck.
Classically, an electron oscillator may vibrate with any frequency or have
energy up to some maximum value. But Planck’s hypothesis states that the
energy was quantized or that oscillators could have only discrete or certain


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