Question

question 7
1 pts
a comparison of the electron configurations of the oxide ion (o²⁻) and the sodium ion (na⁺)
indicates that
you cannot compare electron configurations of ions.
the oxide ion and the sodium ion are isoelectronic.
the sodium ion has 2 fewer p electrons and 1 fewer s electron than the oxide ion.
the oxide ion has 2 fewer p electrons and 1 fewer s electron than the sodium ion.

question 8
1 pts
which of the following elements is not paramagnetic?
fe
zn
br
k

Explanation:

• Question 7:
• An isoelectronic species have the same number of electrons.
• The atomic number of \(O\) is \(8\). For \(O^{2 -}\), the number of electrons \(=8 + 2=10\).
• The atomic number of \(Na\) is \(11\). For \(Na^{+}\), the number of electrons \(=11- 1 = 10\).
• So, \(O^{2-}\) and \(Na^{+}\) are isoelectronic.
• Question 8:
• Paramagnetic substances have unpaired electrons.
• The electron configuration of \(Fe([Ar]3d^{6}4s^{2})\) has unpaired \(d\) - electrons.
• The electron configuration of \(Br([Ar]3d^{10}4s^{2}4p^{5})\) has unpaired \(p\) - electrons.
• The electron configuration of \(K([Ar]4s^{1})\) has an unpaired \(s\) - electron.
• The electron configuration of \(Zn([Ar]3d^{10}4s^{2})\) has no unpaired electrons.

Answer:

• Question 7: The oxide ion and the sodium ion are isoelectronic.
• Question 8: \(Zn\)