Jason 發問於 科學及數學化學 · 1 十年前

Form 3 Elements 問題

Elements A and B have the electronic arrangements 2,8,7 and 2,8,8,7

A ) Which one is more reactivity? Why?

B ) Which one has higher boiling point? Why?

3 個解答

  • 1 十年前

    A) Both of them are belong to the group 7 (halogen) since they 7 electrons in the outermost shell. Element A is more reactive. Unlike group 1, group 7 reactivity decreases down under the group and the element is arranged by atomic number so element A has a higher posistion than B in group 7. So element A is more reactive.

    B) Element B has higher boiling point. Sine the state of the element in group 7 is graudually change from gas state to soild state down to the group. Since element B has a lower position than element A . So it has higher boiling point

  • 志仁
    Lv 6
    1 十年前

    a) A, since the size of the A is smaller, the atom catch electron easier.

    b) B, since the size and weight of B is larger, more energy is need to make the atom to vapourize.

  • 1 十年前

    A) A. In group VII,reactivity decrease down the group.

    B) B. In group VII,the state of element gradually change from gas to soild.

    資料來源: me