Two students are given different samples of a substance and are instructed to determine the properties of the substance. which statement describes a property that will be the same for both students?

-color because it is an extensive property
-mass because it is an extensive property
-boiling point because it is an intensive property
-volume because it is an intensive property

I think its B: mass because it is an extensive property

Explanation:

the answer for sodium is 0.186

the answer for rubidium is 0.251

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.