Data Analysis and Conclusion
You would know a decomposition reaction occurred if the reactants separated. For example from AB → A+B.
Now if you look at your options only 1 works out for that equation. Letter A.
From the compound K2CO3 it split up to K2O +CO2
It cannot be letter B because synthesis/combination occurred. The same goes for letter C. Letter D, single displacement occurred.
Again, the answer is A.
If the ball is green, then it is absorbing all the colors of light except green. This means that it is reflecting or denying the absorption of green light, that is why the ball is green. Therefore, your answer would be B.
Hope I helped :)
About 85% sure on this one.
Wrapping in insulated wire around a medal with ferromagnetic properties and applying an electric current