Define aqua regia and write a short note on it

Explanation:

Aqua regia is a strong and very concentrated acid formed by mixing Hydrochloric acid(HCl) and nitric acid.

The acid is very corrosive due to its formulation and it nearly reacts to dissolve all substances including the unreactive gold metal. It is formed by mixing the two acids in a proportion of 1:3, i.e HCl in 3 parts and nitric acid in 1 part.

The mixture dissolves a wide range of metals

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.