Agas quickly expands in an isolated environment. during the process, the gas exchanges no heat with its surroundings. the process is:
a. isobaric
b. isotonic
c. isothermal
d. isochoric
e. adiabatic

e. adiabatic process

Explanation:

Adiabatic process  -

In the thermodynamic system , an adiabatic process is the one which involves no transfer of mass or heat of the substance , is referred to adiabatic process.

In this process , the temperature need not be constant ,

But only the heat is transferred into or out of the system .

Hence, from the given information of the question,.

The correct option is e. adiabatic process .

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.