I believe it's better for it to be more abundant because it's better to have more then less. Take water as an example. Water is an important factor to our survival and if we didn't have enough of that we would be in trouble. Or if we needed food but there wasn't enough more people would be dying from starvation. It's better to have a little more than a little less.
Answer:
Chopping wood logs
A pot of water o a grate over a burning fire
Explanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
Explanation:
It should be equal to the mass of the carbon plus the mass of the oxygen. This is because of the conservation of mass law. Mass is never created or destroyed only conserved. Hope this helped