(4) Pb+PBO _ 2+2h2so4 discharge 2pbso4+2h2o (5) zero valence and +4 valence.
Test and analysis: (1) The content of macro elements (1 1) in human body >: 0.0 1%, in which ca >:P>；; K>S & gtNa & gtCl & gtMg, so chlorine is a constant element needed by human body;
(2) French fries belong to starch, and the nutrients that can provide energy for human body in fried French fries are mainly sugar (3) oil;
(4) Vitamins can regulate metabolism, prevent diseases and maintain health.
(5) Under the discharge condition, lead, lead dioxide and sulfuric acid are mixed to produce lead sulfate (PbSO 4) and water, so the chemical equation of the reaction is Pb+PbO 2 +2H 2 SO 4 discharge 2PbSO 4 +2H 2 O.
(6) According to the general law of valence: in the compound, the algebraic sum of positive and negative valence is 0, in the simple substance, the valence of elements is 0, so the valence of Pb before the reaction is 0, while in PbO 2, the valence of O is -2, so the valence of Pb is +4.