①随着核电荷数的增加，碱金属单质、卤素单质的熔沸点依次升高，密度依次增大

②F、Cl、Br、I的最外层电子数都是7，次外层电子数都是8

③碱金属单质的金属性很强，均易于氧气发生反应，加热时生成氧化物R₂O

④砹是原子序数最大的卤族元素，根据卤素性质的递变规律，At与H₂化合最容易

⑤从HF、HCl、HBr、HI酸性递增的事实，推出F、Cl、Br、I的非金属性递增规律

⑥碱金属都应保存在煤油中

⑦卤素按F、Cl、Br、I的顺序其非金属性逐渐减弱的原因是随着核电荷数增加，电子层数增多，原子半径增大起主要作用

⑧碳酸铯不易发生分解反应生成氧化铯和二氧化碳．

从方框中选择恰当的句子补全对话。（其中有两个多余）
A: Hi, Mikc!
B: Hello!
A:____ 
B: Yes, but one thing annoyed me.
A: ____ 
B: On the bus, I saw a woman eating bananas and threw the banana skins out to the window.
A: ____ 
B: I told her what she did was not right.
A: You were right. Throwing the litter away will pollute the environment.
B: I Agree with you.
A: ____ 
B: She didn’t take my words at all.
A: No wonder(难怪) you are so angry.