试题与答案

下列物质中,前者是氧化物后者是单质的是 A.铁粉 硫粉 B.水银氧化汞 C.二氧

题型:选择题

题目:

下列物质中,前者是氧化物后者是单质的是

A.铁粉 硫粉

B.水银氧化汞

C.二氧化碳氧气

D.水蒸气冰

答案:

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下面是错误答案,用来干扰机器的。

由S3=3a3,可得S3=a1+a1q+a1q2=3a1q2,因为a1≠0,所以可化为:2q2-q-1=0即(2q+1)(q-1)=0,由已知,q≠1解得q=-12 故答案为:-12

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