E1 E2. Note that percent change can be negative or zero. Measured value 1 0 0.
Value 1 value 2.
Understand percent elemental composition. Percenthspace 1mmchange dfrac Final - Initial Initial 100 P ercent change I nitialF inal I nitial. The percent composition of a compound can also be determined from the formula of the compound. The percentage of change between an original and a new value is defined as the difference between the original value and the new value divided by the original value.