Molar mass of iron(III) oxide is 160g/mol
160g ----------- of iron(III) oxide is ---------------- 6.02*10²³molecules
79g ----------- of iron(III) oxide is ---------------- x
x = [6.02*10²³*79g]/160g ≈ <u>2.97*10²³ molecules</u>
Ionization energies evidence for the quantization of energy levels in atoms, as described by the Schrodinger wave mechanical model of the atom because it takes a specific amount of energy to remove the definite one electron from an atom.
Explanation:
- Ionization energies evidence for the quantization of energy levels in atoms, as described by the Schrodinger wave mechanical model of the atom because it takes a specific amount of energy to remove the definite one electron from an atom.
- There is an approximate amount of energy which is needed to overcome the attractive force between the electrons and nucleus.
- If you put less than the required ionization energy, then the electrons can not be removed.
Example: A sodium atom contains 11 protons, so its atomic number is 11. Mass number is the total of the protons and neutrons together, and it is given the symbol A. Example: A sodium atom contains 11 protons and 12 neutrons; its mass number A is 23<span>.</span>
Answer:- 123 amu.
Solution:- The formula to calculate the average atomic mass of an atom is:
Average atomic mass = mass of first isotope(abundance of first isotope) + mass of second isotope(abundance of second isotope)
Note: The percent abundance is converted to decimals.
mass of Sb-121 is 121 amu and it's percent abundance is 57.3% and in decimal it is 0.573. Percent abundance of Sb-123 is 42.8% and in decimal it is 0.428. We are asked to calculate it's mass. The average atomic mass of Sb is given as 122.
Let's say the mass of Sb-123 is M and plug in the values in the formula and do calculations:
122 = 121(0.573) + M(0.428)
122 = 69.333 + M(0.428)
On rearrangement:-
M(0.428) = 122 - 69.333
M(0.428) = 52.667
M = 123
So, the mass of Sb-123 is 123 amu.
