Оценка:
Опубликованно: 01.12.1996.
Язык: Английский
Уровень: Средняя школа
Литературный список: Нет
Ссылки: Не использованы
  • Эссе 'Lead and Environment', 1.
  • Эссе 'Lead and Environment', 2.
Фрагмент работы

Some materials are so commonplace that we take them for granted. One of those materials is a grayish metal that has been with us for thousands of years. That metal is lead,
still one of the world's most useful substances, and one that never ceases to find a role in human society.
Lead has the atomic symbol of Pb (for plumbum, lead in Latin). The atomic number for lead is 82 and the atomic mass is 207.19 AMU. It melts at about 327.502 oC and boils at
1740 oC. Lead is a heavy, ductile, soft, gray solid. It is soluble in nitric acid and insoluble in water. It is found in North, Central and South America, Australia, Africa and Europe.

Atlants