What is the enthalpy of reaction for the
decomposition of NO2(g)?
2NO2(g) → N2(g) + 2O2(g)
KJ
This reaction is

THE ANSWER IS -67.68

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?