Martina has a sample of an unknown substance. She measures the substance. Its mass is 13. 5 grams, and its volume is 5 cm3. Which metal might her sample be made of?.

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.

it would be d. henry moseley

hope this !

and sorry if i'm late. have a good rest of your day! : d