Answer:
B.
Explanation:
When water separates into hydrogen and oxygen gas, a decomposition reaction is taking place (one substance breaking apart or breaking down into two or more substances).
The law of conservation of mass tells us that mass is not created or destroyed during a chemical reaction, so the total mass will remain the same. This is supported by the diagram on the page, which shows that in the reactants, there are four hydrogen atoms and two oxygen atoms, and this amount is the same on the product side.
Answer: 105 centimeters
Explanation:
1 meter = 100 centimeters
105 centimeters = 1 meter and 05 centimeters
Answer:
The oxidation number of an atom is the charge it appears to have when you count the electrons according to some arbitrary rules. The oxidation number of an atom depends on the other atoms in the substance.
Explanation:
For example, In KCl, the oxidation number of Cl is 0.
Answer: D.two or more elements are chemically bonded
Explanation:
Compound is a pure substance which is made from atoms of different elements chemically combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. They have different properties as compared to their constituents. Example: water 

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper 
Thus every compound is made up of two or more elements chemically bonded.