氢在化学元素周期表中排在第一位,它是最轻的化学元素。在一般情况下,它是一种气体。提起氢气,许多人都不会感到陌生。像探测高空气象所用的气球,节日里放出的彩色气球,大都是充以氢气(不过,由于氢气球容易发生爆炸,所以今天的气球人都已经改用氦气)。在切割钢铁或焊接钢铁的时候,人们所用的氢气 Hydrogen ranks first in the chemical periodic table, which is the lightest chemical element. In general, it is a gas. Lift hydrogen, many people will not feel strange. Like balloons used to detect high-altitude weather, most of the colored balloons that are released during the festival are filled with hydrogen (however, today’s balloons have been switched to helium because hydrogen balloons are prone to explosions). People use hydrogen when cutting steel or welding steel