? asked in 科學及數學化學 · 1 decade ago

s.3 既Chem&Phy

Chem: Iron(II)Sulphur算唔semimetal

佢係metal, semimetal or non-metal???

Phy:If I know (convex lens) the focal length,the objet distance and object size....

then how can i know the image distance???係咪有條formula???

2 Answers

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  • 1 decade ago
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    I think you mean iron(II) sulphide, FeS.

    Iron(II) sulphide is an ionic compound, but not an element. Only an element can be classified into a metal, a non-metal or a metalloid. Therefore iron(II)sulphide is neither a metal, nor a non-metal, nor a metalloid.

    In the CE Structural Question, you have no other means but to draw the actual ray diagram in order to find the image distance.

    Nevertheless, in MC, you may use a out-of-the-syllabus formula:

    1/u + 1/v = 1/f, where u, v and f represents the object distance, the image distance and the focal length respectively.

  • 1 decade ago

    chem:

    semi- metal 既意思即係有種元素,

    有d特質同 metal 相同,而有d 就同metal 唔同。

    雖然 Iron 係 metal,而 Sulphur 唔係,但呢個而已唔再係 element,

    呢個係 ionic compound,即係金屬同非金屬既混合物。

    phy :

    放大率

    = 像高( image size )/ 物高 ( object size )

    = image distance / objectdistance

    睇下有無用呢條式~

    Source(s): myself 我是 from5 的
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