12. The atomic mass of titanium is 47.88 atomic mass units. This atomic mass represents the
total mass of all the protons and neutrons
in an atom of Ti
2. total mass of all the protons, neutrons, and
electrons in an atom of Ti
3. weighted average mass of the most
abundant isotope of Ti
4. weighted average mass of all the naturally
occurring isotopes of Ti

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.  

if the temperature drops and becomes cool

then the atmosphere can be freezing as the water vapor in the air is at maximum (100%) and can be severely cold

also can be snowing lightly as the moisture in the air will start to solidify

and btw this is not chemistry but