Acopper sheet is heated in a furnace until it melts. the hot liquid copper is then cooled until it becomes solid again. compare the mass of the copper before and after melting. a) the new solid copper is lighter than the original sheet. eliminate b) the new solid copper is heavier than the original sheet. c) the new solid copper is the same weight as the original sheet. d) the molten copper was lighter than the sheet or the new solid.

Temperature and kinetic energy are proportional. a) adirectly b) directly c) indirectly

The following reaction shows the products when sulfuric acid and aluminum hydroxide react. al(oh)3 + h2so4 → al2(so4)3 + h2o the table shows the calculated amounts of reactants and products when the reaction was conducted in a laboratory. sulfuric acid aluminum hydroxide initial amount of reactant 40 g 15 g theoretical yield of water from reactant 14.69 g 10.38 g what is the approximate amount of the leftover reactant? 11.73 g of sulfuric acid 10.33 g of sulfuric acid 11.12 g of aluminum hydroxide 13.67 g of aluminum hydroxide

In the cathode ray tube experiment, j. j. thomson passed an electric current through different gases inside a cathode ray tube in the presence of an electric field. in which two ways did this experiment change scientists’ understanding of the atom?