If you have a bag that contains 100 pencils of different colors and lengths, describe how you could order the pencils in a way that would follow a pattern similar to the organization of elements on the periodic table.

2b2t

explanation:

2b2t

answer; 4 electrons;

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.

they are called fossil fuels