The average atomic mass of the imaginary element : 47.255 amu
<h3>Further explanation </h3>
The elements in nature have several types of isotopes
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ..
isotope E-47 47.011 amu, 87.34%
isotope E-48 48.008 amu, 6.895
isotope E-49 50.009 amu, 5.77%
The average atomic mass :

Atoms are the basic units of matter and the defining structure of elements. We count the number of atoms by the total number of elements present in the compound. In this case, we have 1 atom of Si and 2 atoms of oxygen which would have 3 total number of atoms.
Answer:
394.99g
Explanation:
The number of moles of a substance can be calculated by dividing the number of atoms of such substance by Avagadro's number (6.02 × 10^23)
n = nA ÷ 6.02 × 10^23
The number of atoms of Fp3BZ2 in this question is 2.45E24 formula units i.e. 2.45 × 10^24
n = 2.45 × 10^24 ÷ 6.02 × 10^23
n = 2.45/6.02 × 10^(24-23)
n = 0.407 × 10¹
n = 4.07moles
Using mole = mass/molar mass
Where; molar mass of Fp3Bz2. is 97.05
g/mol.
mass = molar mass × mole
mass = 97.05 × 4.07
mass = 394.99g