帮你写了一小段：
White lead is a kind of oil paints,which is really widely used in art.
And the chemical formula is Pb(OH)2·2PbCO3.
We know air contains hydrogen sulphide(H2S),which can react with white lead and generate lead sulfide(PbS).Lead sulfide is black,so white lead has a peoperty,that is,it slowly becomes black in air.
翻译成中文就是：铅白是一种在美术上广泛使用的油画颜料,它的化学式是Pb(OH)2·2PbCO3.我们知道空气中含有硫化氢,它能和铅白反应并生成黑色的硫化铅,这使得铅白具有在空气中慢慢变黑的性质.