A. [1,2] sigmatropic hydrogen migration
Answer:
is missing
Explanation:
In a nuclear reaction, the total mass and total atomic number remains the same.
For the given reaction:

To calculate A:
Total mass on reactant side = total mass on product side
4 + 9 = 12 + A
A = 1
To calculate Z:
Total atomic number on reactant side = total atomic number on product side
2 + 4 = 6 + Z
Z = 0

Hence, missing is
.
Explanation:
Substances generally tends to specialize as either oxidizing or reducing agents.
An oxidizing agent is an electron acceptor which causes a co-reactant to be oxidized in a reaction.
Examples are:
Non-metals especially oxygen and the halogens.
Other examples are H₂SO₄ , HNO₃, KMnO₄, K₂Cr₂O₇
learn more:
Oxidizing and reducing agents brainly.com/question/5558762''
#learnwithBrainly
Answer:
To make baking powder, combine half a teaspoon of cream of tartar and a quarter teaspoon of bicarbonate of soda.
hope it helps;)