BBC12 年
What does the periodic table tell us about the elements?
Damp litmus paper is bleached white when it is placed in chlorine. If damp-blue litmus paper is used, the paper turns red then white.
BBC1 年
Chemical properties of the group 7 elements
Damp litmus paper is bleached white when it is placed in chlorine. If damp-blue litmus paper is used, the paper turns red then white.