14C是C的一种放射性核素，在高层大气中由宇宙射线产生的中子或核爆炸产生的中子轰击14N可使它转变为14C。下列说法正确的是
A．14C和14N互为同位素 B．14C原子最外层有6个电子
C．14C核素中的中子数为8 D．14CO2的摩尔质量为46
答案：C
考查原子结构
A．同种元素的不同原子才能互称为同位素，排除
B．14C原子最外层有4个电子，不正确
C．14C核素中的中子数为14-6=8，正确
D．14CO2的摩尔质量为46g/mol，排除
答案为C
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| When I was a boy, every holiday that I had seemed wonderful. My 1 took me by train or by car to a hotel by the 2 . All day, I seem to remember, I 3 on the sands with strange 4 children. We made houses and gardens, and 5 the tide (潮汐) destroy (破坏, 毁坏) them. When the tide went out, we 6 over the rocks and looked down at the fish in the rock-pools. In those days the 7 seemed to shine always brightly 8 the water was always warm. Sometimes we left the beach and walked in the country, 9 ruined (毁灭的) houses and dark woods and climbing trees. There were 10 in one's pockets or good places where one could 11 ice-creams. Each day seemed a life-time. Although I am now thirty-five years old, my idea of a good 12 is much the same as it was. I 13 like the sun and warm sand and the sound of 14 beating the rocks. I no longer wish to 15 any sand house or sand garden, and I dislike sweets. 16 , I love the sea and often feel sand running through my fingers. Sometimes I 17 what my ideal (理想的) holiday will be like when I am 18 . All I want to do then, perhaps, will be to lie in bed, reading books about 19 who make houses and gardens with sands, who watch the incoming tide, who make 20 sick on too many ices... | ||||
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