Assume that the typical American household requires 837 kilowatt hours (kWh) of electricity per month. This equates to 3 × 109 joules. How much methane must be burned to produce the average American household’s total annual electricity consumption? the energy density of methane is 55.63

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e