题干

下列关于元素第一电离能的说法不正确的是(  )

A:钾元素的第一电离能小于钠元素的第一电离能,故钾的活泼性强于钠

B:因同周期元素的原子半径从左到右逐渐减小,故第一电离能必依次增大

C:最外层电子排布为ns2np6(当只有K层时为1s2)的原子,第一电离能较大

D:对于同一元素而言,原子的电离能I1<I2<I3<…

上一题 下一题 0.0难度 选择题 更新时间:2020-01-03 01:10:59

答案(点此获取答案解析)

B

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阅读下列短文,从每题所给的四个选项(A、B、C、和 D)中,选出最佳选项。

    Hello. I'm Jan from Mrs. Lake's class. My class wants to work together to help the public. We think we have found a great way to do this. Last month we did a class project on the highways near our town. We learned about the Adopt-a-Highway Program. This program brings people together to pick up litter along the roads. We think it would be a great idea for all students in our school to join the program and adopt(收养) a highway.

    Adopting a highway is not like adopting a pet. When a highway is adopted, only part of the highway is cared for by a group of people. The group agrees to work every week to keep its part of the highway clean. Each group gets its own sign that has the name of the group printed on it. The sign is put up at the side of the road . This sign lets drivers know who is keeping that area of the road clean.

The Adopt-a-Highway Program is a great way for people to help their environment look nicer. Also, the government does not have to send out as many road workers. This saves money. Finally, people may try harder to keep roads clean if they see people, especially teenagers like us, cleaning them up.

     We will need helpers to care for our adopted highway. If you want to feel great and keep our roads clean,please come with your parents to the meeting next week. We will meet in Mrs. Lake's room on Wednesday at 6:00 P.M. At the meeting, we will talk about which roads are the dirtiest as a result of people's unkind acts. Then we'll try to pick an area to adopt and clean.

    I look forward to seeing you at the meeting. Remember to keep our roads clean!