Three isotopes of silicon have mass numbers of 28,29, and 30 with an average atomic mass of 28.086 what does this say about the relative abundances of the isotopes

Answer is: silicon isotope with mass number 28 has highest relative abundance, this isotope is the most common of these three isotopes.

Ar₁(Si) = 28; the average atomic mass of isotope ²⁸Si.  

Ar₂(Si) =29; the average atomic mass of isotope ²⁹Si.  

Ar₃(Si) =30; the average atomic mass of isotope ³⁰Si.  

Silicon (Si) is composed of three stable isotopes, ₂₈Si (92.23%), ₂₉Si (4.67%) and ₃₀Si (3.10%).

ω₁(Si) = 92.23%; mass percentage of isotope ²⁸Si.  

ω₂(Si) = 4.67%; mass percentage of isotope ²⁹Si.

ω₃(Si) = 3.10%; mass percentage of isotope ³⁰Si.

Ar(Si) = 28.086 amu; average atomic mass of silicon.  

Ar(Si) = Ar₁(Si) · ω₁(B) + Ar₂(Si) · ω₂(Si)  + Ar₃(Si) · ω₃(Si).  

28,086 = 28 · 0.9223 + 29 · 0.0467 + 30 · 0.031.

false

because it does not have the potential to be entirely used up

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."