Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.




Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give
which written in simplest whole number ratios to give neutral 
This represents a primary amine. An amine has a nitrogen group that is connected to three substituents via single bonds. The number of carbon-based substitutents determines whether it is primary, secondary, or tertiary. In this case, since 2 substitutents are just hydrogen atoms, and only one has a carbon-based skeleton, this is a primary amine.
White light is what the eye sees when wavelengths of all colours reach the eye.
It is a combination of Red, Blue and Green wavelengths of light, that is perceived as white.
Answer:
OH^-
Explanation:
Any substance that is able to neutralize acidity in the stomach is generally known as an antacid. There are various kinds of antacids that are in common use. It should be noted that the stomach is usually slightly acidic.
Milk of magnesia is the substance magnesium hydroxide with chemical formula Mg(OH)2. A solution of milk of magnesia contains Mg^2+ and OH^-.
Hence the negative ion contained in milk of magnesia is the hydroxide ion OH^-.