CH4+O2—-CO2+H2O what is the best classification for the unbalanced equations reaction and why

How are isotopes of the same chemical element alike? how are they different?

What is another way to determine mass times acceleration?

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.