The object that goes through chemical change, changes completely to where you can not change it back to its original form. Physical change you can undo
B. Decreasing surface area of a solid reactant. The more surface area showing, the quicker the reaction rate.
Hey user
The energy E in joules (J) is equal to the voltage V in volts (V), times the electrical charge Q in coulombs (C):
E(J) = V(V) ×<span> Q</span>(C)
So
joule = volt × coulomb
or
J = V × C
Example
What is the energy in joules that is consumed in an electrical circuit with voltage supply of 15V and charge flow of 4 coulombs?
E = 15V × 4C = 60J
