Please help if you can 2H2(g) + O2(g) → 2H2O(l)

The chemical equation above describes a(n).
A). endothermic change
B). reversible state change
C). chemical change
D). physical change

In numbering carbon atoms in the parent chain of a hydrocarbon, why would you number from right to left, rather than left to right

Which atom or ion is the largest? 0 a. 0 0 0 0 e. li

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.