Chemical. Burning is a chemical process
Answer : The volume occupied by lead is, 2.20 mL
Explanation :
Density : It is defined as the mass contained per unit volume.
Formula used for density :

Given :
Mass of an lead = 25.0 grams
Density of lead = 11.34 g/mL
Now put all the given values in the above formula, we get the volume of lead.


Therefore, the volume occupied by lead is, 2.20 mL
Answer: one molecule of O2.
Explanation: sweet i just took a guess but I believe that if 3 o2 molecules - 2 h2 molecules I think that its just basic maths and it is C because 3-2 = 1 and its o2 remaining, sorry if I’m wrong.