Why is the current atomic model called the "electron could model"

Adding more pulleys to a system of pulleys needed to lift an object. a. increases the force b. decreases the force c. increases the amount of work d. decreases the amount of work

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)

In a system, when potential energy decreases, then entropy also decreases. true false