Answer:
Explanation:
The valance of magnesium atom is 
While the valence of nitrogen atom is 
Let us first write the first half-reactions
The second half reaction is
Adding the above two reactions and writing the final reaction, we get -
The balance equation is
Answer:
Only 4 %
Explanation:
Just about 4 percent of the known universe overall mass consists of atomic nuclei and is therefore described by chemical components. This proportion is around 15 percent of the total mass, with dark energy becoming the majority of the material .
Copper oxide<span> is a base because it will react with acids and neutralise them, but it is</span>not<span> an alkali because it </span>does not dissolve in water. Sodium hydroxide is a base because it will react with acids and neutralise them. It's also an alkali because itdissolves in water<span>.</span>
