Which change would keep this reaction from shifting to form more of the product?
2802 + O2 22803 + energy
A. Decreasing the pressure in the reaction vessel
B. Removing the product from the reaction vessel as it forms
C. Increasing the pressure in the reaction vessel
D. Decreasing the temperature in the reaction vessel

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.  

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.