An aqueous solution of sodium chloride is best classified as a

An aqueous solution of sodium chloride is best classified as homogeneous mixture.

Explanation:

Homogeneous mixture:

In homogeneous mixture solute particles are fully dispersed in solvent. In homogeneous mixture solution is present in liquid phase but the phase of solute and solvent can vary.

For example in case of sodium chloride solution, solid sodium chloride is dissolved in to the solvent i.e water. The partial negative charge of water surrounded the cationic part of sodium chloride i.e (Na⁺)  and partial positive part of water surrounded the anionic part of sodium chloride (Cl⁻) in this way sodium chloride is splitted into ions and get dissolved in water and make an homogeneous solution.

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.  

answer; talc and gypsum;