Copper (Cu) reacts with sulfur (S) to form copper sulfide. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction. At the end of the experiment, there are 15.9 grams of copper sulfide. In this reaction, all of the copper and Science SAU7: Chemical Change Test Study Guide all of the sulfur react. The scientist then tries to add 13.7 grams of Cu to 3.2 grams of S. There are still 15.9 grams of copper sulfide at the end, but some copper is also left over. In 1-2 sentences, explain how to calculate the amount of remaining copper. Use the law of conservation of mass in the explanation.

Oxidation-reduction reactions (often called "redox" for short) are reactions that involve the transfer of electrons from one species to another. oxidation states, or oxidation numbers, allow chemists to keep track of these electron transfers. in general, one element will lose electrons (oxidation), with the result that it will increase in oxidation number, and another element will gain electrons (reduction), thereby decreasing in oxidation number. the species that is oxidized is called the reducing agent or reductant. the species that is reduced is called the oxidizing agent or oxidant. to sum up: oxidation = increase in oxidation state = loss of electrons = reducing agent reduction = decrease in oxidation state = gain of electrons = oxidizing agent part a which element is oxidized in this reaction? fe2o3+3co→2fe+3co2 enter the elemental symbol. view available hint(s) is oxidized part b which element is reduced in this reaction? 2hcl+2kmno4+3h2c2o4→6co2+2mno2+2kcl +4h2o enter the elemental symbol. view available hint(s) is reduced

The best solution for preventing harm to people and pets from severe hurricanes involves determining and warning residents about what

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.