When an ecosystem changes the results are (positive negative both or none) explain This is science!

How many atoms are there in 5.70 mol of mg

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?

For the reaction shown, calculate how many moles of no2 form when each of the following completely reacts. 2n2o5(g)→4no2(g)+o2(g) part a 1.0 mol n2o5 express your answer using two significant figures. nothing mol m o l request answer part b 5.4 mol n2o5 express your answer using two significant figures.