Is a burning log an exothermic or endothermic event if the log is the system?

What is the most stable monatomic ion formed from nitrogen

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

Which statement is true about the model of the electromagnetic spectrum a: it change the frequencies of light. b: it compare wavelengths of light. c: the color of light waves can be changed using the model. d: the intensities of light waves can be decreased using the model.