Elect all of the true statements regarding chemical equilibrium. The concentrations of reactants and products are equal. The concentrations of reactants and products remain constant. Reactants are being converted to products and vice versa. The rates of the forward and reverse reactions are equal.

The correct statements are:

Explanation:

Equilibrium defined as state of the reversible reaction where extend of reaction moving froward is equal to the extend of reaction moving backwards.

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.