Marie has an electromagnet that she wants to use to help her lift some metal. Before she installs the electromagnet into the lifting machine, she decides to investigate the magnetic field to increase as much as possible the magnet’s strength and range. She identifies an independent variable that she will vary and a dependent variable, the magnet’s strength and the range. Fill out the investigation planning worksheet below to show how Marie plans her experiment:

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.