1. What type of reaction is this? H2O + H2 + O2
A. Synthesis
B. Decomposition
C. Combustion
D. Single Replacement
E. Double Replacement

I say synthesis

B if you meant ->

Explanation:

A. Synthesis: reaction where two or more reactants combine to form one product. A+B->AB

B. Decomposition: reaction where a single compound reacts to form more than one product. AB-> A+B

C. Combustion: any reaction in which a substance reacts with oxygen gas. (needs )

D. Single replacement: a type of reaction where one element replaces a similar element within a compound. Reaction is always an element and a compound.

E. Double replacement: a type of reaction where the ions of two compounds exchange places in an aqueous solution to form two new compounds. AB+CD->AD+CD

the answer is true. hope it .