In a chemical reaction, the reactants are substances that undergo the reaction, and the products are substances that are formed during the reaction. the table below shows the reactants and products of several different chemical reactions. reactants products type of reaction 4k + o2] [2k2o + heat] exothermic 2h2o + heat] [2h2 + o2] endothermic 2co + o2] [2co2 + heat] exothermic caco3 + hea] [cao + co2] endothermic based on the information given in the above table, the best definition of an endothermic reaction would be? a. a reaction that releases heat. b. a reaction that absorbs heat. c. a reaction that has one product. d. a reaction that does not require heat.

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.