Independent Variables are changes that occur in an experiment that are directly caused by the experimenter (you.)
Dependent Variables are changes that occur due to independent variables.
Controlled Variable is anything else that could influence the dependent variables.
Number 1 is a synthesis reaction because two compounds/elements are coming together to form one compound
In descending order from top:
E
F
D
A
C
B
All you really need to do is remember the symbols of each, and you’ve got it.