A student can hold her breath for 94 seconds if another student records that the time she can hold her breath is 92 seconds, what is the percent error in this measurement?

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

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

the product of the pressure and volume is also constant