某种氧原子的原子核内有8个质子和8个中子，另一种氧原子核内有8_爱下问搜题

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问题选择题

某种氧原子的原子核内有8个质子和8个中子，另一种氧原子核内有8个质子和10个中子，则这两种原子中不同的是（　　）

A．核电荷数

B．核外电子数

C．中子数

D．原子的带电量

答案

根据在原子中，原子序数=质子数=核外电子数=核电荷数，依据题意可知两种氧原子质子数=8=核外电子数=核电荷数，由此可知选项A，B．D不合题意，因两种氧原子的中子数不同，选项C符合题意．

故选C．

完形填空

To my family and friends,
As some of you know, I have just started my tour in the remote mountain area. Everything is going really well, so no      .The land is beautiful but unfortunately it has a lot of        too. I have received several emails asking what I need while I'm here .so I decided to write you all and let you know that I don’t need anything. At least not for me. I’m asking all of you to send me a few       to help the local children. Let me explain.
On 12 May 2009, in a small village here, 120 school age girls were       by a gas leak（煤气泄漏）. Most have      but 6 are still in hospital. Even though the local government speaks about the     of education for both boys and girls but most of these kids only attend school for four hours a day if they are even allowed to go. They are so excited and     to learn, but then have to     things like being sprayed（喷射） with acid or poisoned. Most of these kids are poor and can’t     a pencil, pen or even paper to write on. So my co-workers and I are planning a trip to several schools to promote      and to give these kids some of the       they need. That is where all of you come in. If you can, please       whatever school supplies you currently have     .
That would be a huge help.
I know how busy you are so thank you for taking the     to do this and I will post pictures of this    after we go.
Thank you again.
Todd Tucker

B．attractions

C．discouraged

C．possibility

A．Information

C．communication

C．responsibility

A．Advertisement

选择题

下图是一正弦交变电流的电流图象．此正弦交变电流的频率和电流的有效值分别为（　　）

A．5Hz，10A

B．50Hz，10A

C．50Hz，10 A

D．5Hz，10 A