4...........................
Explanation:
A synthesis reaction: It is defined as a kind of reaction where one and more than one reactant attached and creates an individual product.
The formation of the water is an example of a synthesis reaction because here more than one reactants combine and create a single product (water). Water formation occurs when 2 hydrogens and an oxygen share electrons through covalent bonds.
2H + O ----> H2O.
I did the test and the answer is C.
D. Two electrons in its first energy level; eight electrons in its second energy level; six valence electrons in its outermost energy level.
Please correct me if I'm wrong!! :)
The most concentrated solution is b
