Which are the reactants in the following reaction? 2 Mg + O2 ---> 2MgO

a)Mg and O
b)Mg and MgO
c)MgO
d)O and MgO

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

What is the percent composition of ca(oh)2? 37.7% ca, 53.0% o, and 10.3% h 45.5% ca, 38.2% o, and 16.3% h 54.0% ca, 43.0% o, and 2.7% h 64.7% ca, 27.0% o, and 8.3% h

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.