题目

从电负性的角度来判断下列元素之间易形成共价键的是( ) A．Na和Cl B．H和Cl C．K和F D．Ca和O 答案：【答案】 B 【解析】一般电负性相差接近的容易相差共价键，H和Cl都是非金属，形成的是共价键，答案选B。在下面对话的空白处填入适当的话语（话语可以是句子、短语或词），使对话完整，并将答案写在答题卡（纸）的相应位置。A: Hello! 【1】?B: Yes, Lucy speaking. Who is that?A: This is Linda. Would you like to go to a movie this weekend?B: 【2】, but I have something important to do.A: What is it?B: Our class is going to visit Old People’s Home.A: I see. 【3】?B: We haven’t decided what to do. Could you give me some advice?A: Let me see... 【4】?B: A party? Good idea! I can play the violin.A: 【5】? I can sing and dance.B: Sure. Let’s get ready for it together.