问题
选择题
在构成原子的粒子中，与元素化学性质关系密切的是（ ）
A．质子数
B．中子数
C．电子总数
D．最外层电子数
答案
元素性质与原子核外电子的排布，特别是最外层上的电子数目有密切关系，所以决定元素化学性质的是最外层电子数．
故选D．
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在构成原子的粒子中，与元素化学性质关系密切的是（ ）
A．质子数
B．中子数
C．电子总数
D．最外层电子数
元素性质与原子核外电子的排布，特别是最外层上的电子数目有密切关系，所以决定元素化学性质的是最外层电子数．
故选D．
| 完形填空。 |
| It took Charlie several months to save up (积蓄) seven dollars. He wanted to 1 a model plane and went to the shop with the money. On the way, Charlie saw a little boy 2 on a corner of the street. 3 are you crying? Charlie asked. Those big boys took 4 my four dollars just now, the boy said, I was on 5 way to buy some exercise-books, but now I can't. Charlie thought of the 6 dollars in the pocket. He though of the model plane and the poor 7 . Charlie wanted to walk away, 8 he did not. At last he 9 four dollars to the boy and went home. Charlie 10 happy. Do you know why? He was happy because the little boy was happy. |
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