题目

After a long day’s study at school, you are very tired. So after school you go home to relax. When you get home, a robot greets you. He’s happy to see you and helps you take your school things to your room. He listens to you talk about your school life and tells you a new joke. And he tells you to call your cousin and to say happy birthday. And then he helps you with your homework.This is your future, and the robot’s name is NAO. NAO has a small body, big eyes and a large head. He can walk and dance. He listens and talks, and he even learns and thinks for himself. His creators (创造者氢化钠（NaH）是一种白色的离子晶体，其中钠是+1价， NaH与水反应放出氢气。下列说法正确的是（      ）。A.NaH在水中显酸性B.NaH中氢离子的电子层排布与氦原子相同C.NaH中氢离子的半径比锂离子的半径大D.NaH中氢离子可被还原为氢气