for the first one it is B OR THE SECOND OPTION
A. Scientific results presented by a scientist should be reproducible anywhere in the world, without this, the results can not be accepted as theory.
Protons, neutrons..................................
Answer:
Double Displacement Reaction
Explanation:
A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.
A) Na2S
b) AlF3
c) O2
d) C6H12O6