问题
选择题
氢元素和氧元素的本质区别是原子的（ ）
A．电子层数不同
B．最外层电子数不同
C．质子数不同
D．中子数不同
答案
元素是具有相同核电荷数（质子数）的一类原子的总称．质子数决定元素的种类，氢元素和氧元素的本质区别是原子的质子数不同．
故选C．
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氢元素和氧元素的本质区别是原子的（ ）
A．电子层数不同
B．最外层电子数不同
C．质子数不同
D．中子数不同
元素是具有相同核电荷数（质子数）的一类原子的总称．质子数决定元素的种类，氢元素和氧元素的本质区别是原子的质子数不同．
故选C．
| 阅读短文，判断句子正(T)误(F)。 | |
Chinese team. The football match is going to be over at six o'clock in the afternoon. Our teachers, Mr Li and Mr Wang, are going to watch the football match with us. We are going there by bus. We think we can come back at about eight in the evening. ( ) 1. There is a football match between a Chinese team and a Japanese team. ( ) 2. The match will be over at four o'clock in the afternoon. ( ) 3. We are going there by train. ( ) 4. Mr Li and Mrs Li are going to watch the match with us. ( ) 5. We will come back at about seven in the evening. |