Magnesium (Mg) + Oxygen (O2) -> Magnesium Oxide (MgO). What kind of change is this?
Magnesium (Mg) + Oxygen (O2) -> Magnesium Oxide (MgO). What kind of change is this?
Since magnesium combines with oxygen to form an entirely new substance (magnesium oxide) with different properties, this is a chemical change (a combination/oxidation reaction).
Re-check your working by substituting the answer back into the original question.