Students observed rust forming on a bar of pure iron. Which of the following provides evidence that the change to the iron bar was a chemical change?The melting point of pure iron is approximately 1,500C. The mass and the volume of the rust can be measured. The iron bar is able to conduct electricity even after rust forms. The rust is a new substance that is not pure iron.

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.