Answer:
The correct answer is option c.
Explanation:
Formula used to determine an average atomic mass :

Mass of isotope Sb-121 = 120.904 amu
Fractional abundance of Sb-121 = 57.21% = 0.5721
Mass of isotope Sb-123 = 122.904 amu
Fractional abundance of Sb-123 = 42.79% = 0.4279
Average atomic mass of Sb:

Correct Answer: Option C
Reason:
<span>The </span>Pauli Exclusion Principle<span> states as '<em>in an atom or molecule, no two electrons can have the same four electronic quantum numbers. Further, an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.</em>'
</span>
Thus, it can be seen that in option C, electrons in last 2 subshell have electrons with same spin, which is a violation of Pauli Exclusion Principle .
Answer
D
Explanation:
They take up usable forms of nitrogen found in soil
<span>The correct answer is the first option. Electron is not found in the nucleus of an atom. The sub-atomic particles of an atom are the
proton, electron and the neutron. An electron has a charge of -1 and a
smaller mass than a proton. Proton has the same mass with the neutron. The
ratio between the mass of a proton and an electron is about 2000. An electron
has an equal value but negative charge with the proton.</span>
Answer:
Copper ions are reduced into copper atoms.
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎
Explanation:
During electrolysis, the positive H⁺ and Cu⁺ ions move to the negative cathode and negative OH⁻ and Cl⁻ ions move to the positive anode.
At cathode, copper ions are preferentially discharged due to the low electromotive force required to discharge them compared to the hydrogen ion. The copper ions gain the two electrons lost by the chloride ions when the are discharged. (2 Cl⁻₍aq₎ → Cl₂₍g₎ + 2e⁻)
Thus the half equation is as follows:
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎