Which best defines partial pressure in a mixture of gases? pressure that is exerted by all the gases of a mixture on the container pressure that is exerted by one gas as if it occupied a container by itself half of the pressure that is exerted by the gases of a mixture on the container sum of the individual pressures that are exerted by two or more gases

pressure that is exerted by one gas as if it occupied a container by itself.

Explanation:

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.