问题
填空题
磷原子核内有15个质子、16个中子，则磷原子核外有______个电子，相对原子质量为______．
答案
∵磷原子核内有15个质子，原子核外的电子数等于核内质子数
∴磷原子核外有 15个电子
∵相对原子质量≈质子数+中子数
∴相对原子质量为 31
故答案为15；31．
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磷原子核内有15个质子、16个中子，则磷原子核外有______个电子，相对原子质量为______．
∵磷原子核内有15个质子，原子核外的电子数等于核内质子数
∴磷原子核外有 15个电子
∵相对原子质量≈质子数+中子数
∴相对原子质量为 31
故答案为15；31．
| 阅读下面语言材料，完成表格中相关内容。 | |
| Ladies and gentlemen, Welcome to England! The weather of England is very changeable (易变的). It can be rainy, sunny, cloudy, windy, stormy, warm, foggy, or cold at any time of the year. If it is raining when you get up in the morning, it can be hot and dry by the afternoon. It may be sunny when you get up, but when you go out, it may be rainy. So don't forget to take an umbrella with you. The west of England is wetter than the east, and the north is cooler than the south. You should be ready for any kind of weather. In England, shops are usually open from 9.00 a.m. to 5.30 p.m. On Sundays, some shops are open from 10.00 a.m. to 4.00 p.m. But a lot of shops are closed. Banks, museums or other places are open from 10.00 a.m. to 5.00 p.m. You can go to the parks at any time. All the cities have buses, trains and taxis. People wait in line for buses and they are unhappy if you push in at the front. Don't forget that traffic goes on the left. Be careful with yourselves when you travel in England! | |
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