问题
选择题
下面有关氧化还原反应的叙述不正确的是( )
A.在反应中不一定所有元素的化合价都发生变化
B.在氧化还原反应中,有一种元素被氧化,肯定有另一种元素被还原
C.在氧化还原反应中,失去电子的物质,一定有元素化合价升高
D.氧化还原反应的本质是电子的转移
答案
答案:B
下面有关氧化还原反应的叙述不正确的是( )
A.在反应中不一定所有元素的化合价都发生变化
B.在氧化还原反应中,有一种元素被氧化,肯定有另一种元素被还原
C.在氧化还原反应中,失去电子的物质,一定有元素化合价升高
D.氧化还原反应的本质是电子的转移
答案:B
Yesterday a school boy is daydreaming in class. Not knowing that he was doing, he put a pen cap into his mouth. A few minutes late, he was terrified to find that he had swallowed it! The teacher was shocking when the boy stood up and said, "I've just swallowed a pen cap." He was quickly sent the nearest hospital. There a doctor examined him and said the best treatment was to take some medicines so that the pen cap could pass natural. Three hours later the boy successfully made it."She is really lucky," said the doctor. "It's not rare that small children put things into their mouths for a fun. It's very danger." | 1. _______ 2. _______ 3. _______ 4. _______ 5. _______ 6. _______ 7. _______ 8. _______ 9. _______ 10._______ |