Which of the following will predict what would happen if the scuba tank were to increase in temperature? A.
The number of particles in the tank would increase.

B.
The density of the gas in the tank would increase.

C.
The pressure exerted by the gas in the tank would increase.

D.
The size of the gas particles in the tank would increase.

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.