1)Where are irons in our body ? 2) Is there some difference in the way metals and non– metals react with acid ?​

iron is found in the red blood cells of your blood called hemoglobin and in muscle cells called myoglobin. Hemoglobin is essential for transferring oxygen in your blood from the lungs to the tissues.

2( non- metals generally do not react with acids but metals react with acids and produce hydrogen gas that burns with a 'pop' sound. You must have noticed that copper does not react with dilute hydrochloric acid even on heating but it reacts with sulphuric 

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.