NEED HELP ASAP. A chemical equation is shown below. KNO3 → KNO2 + O2 What are the coefficients that should be added to balance this equation? Use complete sentences to explain your answer. Explain how this chemical reaction demonstrates the conversation of mass.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

c. orbital shape i hope this is correct

im doing test rn im going with 2 but ill give answer if itss wrong,   : )