题目

Paris is the capital of the European nation of France. It isalso one of the most beautiful and most famous cities in the world.  Parisis called the City of Light.It is also an international fashion centre. What modern women are wearing in Paris will soon be wornby many women in other parts of the world. Paris is also a famous world center ofeducation. For instance, the headquarters of UNESCO, the United NationsEducational, Scientific, and Cultural Organization, is in Paris.  The Seine Riverdivides the city into two parts. Thirty-two bridges cross this scenic river.The oldest and perhaps most钠原子的质量数为23，中子数为12，那么它的核外电子数是________,质子数是________。