Which reaction results in only a physical change?
A. 2H2O(l) + electricity ® 2H2(g) + O2(g)
B. 2H2O2(l) ® 2H2O(l) + O2(g)
C. 2H2(g) + O2(g) ® 2H2O(l)
D. H2O(l) + heat ® H2O(g)