资讯
dip a clean wire loop into a solid sample of the compound being tested put the loop into the edge of the blue flame from a Bunsen burner observe and record the flame ...
IN a communication from my zealous science-master, which I find in your issue of Thursday the 11th, it is stated that pure hydrogen has no tinge of blue in its flame (that colour being due to the ...
当前正在显示可能无法访问的结果。
隐藏无法访问的结果