题干

根据《中国广播电视报》报道,在暑天就诊的小病人,低锌发病率高达60%以上.由于锌对人体代谢起着重要作用,因此儿童生长发育时期测量体内含锌量已成为体格检查的重要内容之一,也引起了我国科技工作者的高度重视.其中比较简单的一种检测方法是取儿童的头发约50g,放在核反应堆中经中子轰击后,头发中的锌元素与中子反应生成具有放射性的同位素锌,其核反应方程式为 3064 Zn+ 01 n→ 3065 Zn. 3065  Zn衰变放射出能量为1115eV的γ射线,通过测定γ射线的强度可以计算出头发中锌的含量.关于以上叙述,下列说法正确的是(   )

A:3064 Zn和 3065 Zn具有相同的核子数

B:3064Zn和 3065 Zn具有相同的质子数

C:放出的γ射线通过磁场一定不偏转

D:γ射线在真空中传播的速度是3.0×108m/s

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答案(点此获取答案解析)

B,C,D

同类题1

Good evening, ladies and gentlemen. Welcome to the nine o’clock Mystery Hour. Today we’ll show you two British stories. We hope you’ll enjoy them.
About 900 years ago two green children arrived in a small village in south England. Their eyes and skin were green and they spoke a strange language. They were very tired and weak, so the people of the village looked after them. The boy died a year later, but the girl grew strong and lived the rest of her life there. And her skin colour turned back to normal day by day. Scientists say that sometimes of people don’t have enough food to eat for a long time, their skin goes very pale and can even turn green.
Loch Ness is the largest lake in Scotland. It’s a very deep and cold lake. For hundreds of years, people have talked about a monster(怪物) called Nessie which lives in the lake. About seventy years ago, two people saw something moving in the lake. They said that the animal was playing and rolling around in the water. Since then many people say they have seen the monster. Their descriptions are always the same. It looks like a dinosaur, with a very long neck and a small head. It has a big bump(包,肿块)on its back. People have tried to photograph the animal, but the pictures have not been very clear. Scientists don’t know whether there is a monster or not. Some say it may be a whale or a very large fish. Some think it’s a snake. Others say there’s nothing at all— nothing but people’s imagination. Maybe we’ll never know what’s in Loch Ness.