题目内容：

关于元素周期表的几个英语问题!懂英语和化学的进~
(iv)The elements in thr first vertical column are called the ________(Alkali metals?对吧)and the reactivity of these elements ______________on moving down the column while those in column 7 are called the ______________and the reactivity of these elements ____on moving down the column
(V) elements in the last column are very unreactive and are called the ______(Noble gases)是吗?
(VI) which elements in column 7of the periodic table will react most vigorously with the element sodium(in column 1)?_______________________
(VII) what substance will be formed as a result of the reaction shown im(VI)
___________________.
再来个
some chlorine gas (cl2）was bubbled slowly through a colourless solution of potassium bromide (KBr) what would you observe?