Given the skeleton equation that follows, if you have 17.5 L of O2, how many moles of Ca are needed to react with the oxygen? Include the three steps you used to arrive at your answer.
Ca + O2 -> CaO

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

i do not get it   at all