Question

What is burning magnesiums reaction type? Synthesis, single replacement, ect..

Answer 1

2Mg +O2 = 2MgO
it is not a single replacement
synthesis may be right

Answer 2

it is oxidation reaction it is a type of oxidation reaction at high temp. ( burning,800 c , or electric spark)
2Mg + O2 = 2MgO

Answer 3

usually oxidation-reduction isn't its own class, since 3 types of reactions could be considered redox: synthesis, decomp, and combustion all involve change of oxidation numbers.

You've got 2 reactants coming together to form a single product. That's just about as solid a synthesis reaction as you'll find.

You might also consider it a combustion, since you're taking something and combining it with oxygen, but when I teach reaction types, I keep this as a synthesis.