hydrogen

• In there compounds, the cyclopentadiene ring has only four hydrogens .
  在这些化合物里，环戊二烯环只有4个氢。
• We now incorporate this condition into the analysis of the hydrogen atom .
  现在我们把这个条件用于分析氢原子。
• Hydrocarbons are molecules containing only hydrogen and carbon atoms .
  碳氢化合物是只含碳原子和氢原子的分子。
• Those that are aligned perpendicular to the plane are called axial hydrogens .
  与平面垂直定向的氢叫做直立氢。
• Inertinities are charcoal-like substance with low oxygen and hydrogen contents .
  惰质体是低氧低氢的类木炭物质。
• The simplest covalently bonded molecule is formed from two hydrogen atoms .
  最简单的共价键分子由两个氢原子组成。
• Another negative feature of hydrogen is that it is hazardous material .
  氢气的另一个缺点是：氢是一种易爆的物质。
• The free alkali metals react immediately with water to liberate hydrogen .
  游离的碱金属直接和水中作用，放出氢气。
• Astronomers have found that many stellar objects contain hydrogen atoms .
  天文学家们已经发现，许多恒星上含有氢原子。
• Fire will take place if the gases hydrogen and oxygen are mixed and ignited .
  如果将氢气和氧气混合并点燃，就会着火。