Write the ground-state electron configurations of the following ions: (a) Li^+,(b) H^-,(c) N^3-,

Write the ground-state electron configurations of the...

Key Concepts

Order of Electron Removal and Addition

When forming ions, electrons are typically removed from the outermost shell (with the highest principal quantum number) first, particularly during ionization to form cations. Conversely, electrons are added to fill orbitals in accordance with the orbital energy levels for anions, ensuring the lowest energy arrangements are achieved.

Noble Gas Shorthand

Noble gas shorthand is a method for writing electron configurations in a compact form by using the configuration of the nearest preceding noble gas to represent core electrons. This simplifies the notation of electron distributions, especially for larger atoms, by focusing on the valence electrons.

Ground State

The ground state of an atom or ion is its lowest energy configuration, where electrons occupy the lowest energy orbitals available. This state reflects maximum stability and is the default arrangement when no external energy perturbs the system.

Electron Configuration

Electron configuration describes how electrons are arranged in atomic orbitals. It is determined by the order of orbital filling (following the Aufbau principle), the Pauli exclusion principle, and Hund's rule. This concept provides a framework for understanding an element’s electronic structure and chemical behavior.

Ion Formation

Ion formation occurs when an atom gains or loses electrons, leading to the formation of anions (electron gain) or cations (electron loss). This process changes the electron configuration compared to the neutral atom, and the adjustments follow the principles of electron removal from or addition to the highest energy orbitals.

Transcript

00:01 In problem 27 of chapter 8, product relationships among the elements and the question is write the ground state electronic configurations of the following ions.

00:13 So the concept behind the question is the office principle.

00:18 So according to the office principle which is used to determine the electronic configuration of an atom or ion.

00:27 So according to this principle, the electrons are filled lower energy.

00:31 Orbitals first.

00:34 So it means if we consider one s orbital and two s orbital, so that means one s orbital having lower energy so which is filled first as compared to two s orbital.

00:45 So now we can see in the first case we have lithium ion.

00:53 So first we can write the ground state electronic configuration and then we can see the ionic configuration.

01:01 So the active number of lithium, that is represent by z which is 3 so i can write 1 s 2 2 s 1 now for lithium plus that mean 1 electron removed from 2s orbital so this become 1st 2 so this is the electronic configuration of lithium 1 so now in the next case we have hydrogen anion so the atomic number of hydrogen is 1 so we can write the electronic configuration 1 s 1 for hydrogen anion so that mean we have to add one electron so this become 1 s 2 now in case of nitrogen the atopic number of nitrogen is 7 so i can write 1 s 2 s 2 to p 3 now for nitride ion which is n3 that mean i have to add 3 more electron in this anion electronic configuration of nitrogen so these three electrons add in the 2p orbital which is the outer shell electrons so this become 1 s2 2 s2 and 2p 6 now in case of fluorine the next case the add key number fluorine is 9 so the ground state electronic configuration of fluorine is 1 s2 2 s2 2p 5 so now in case of fluoridine we have to add 1 electron so this 1 electron in 2b orbital so the electronic configuration become 1 s2 2 s2 and 2p 6 so now in the next case we have sulfur so in case of sulfur we can write the electronic configuration as we know the atom number of sulfur is 16 so we can write this is neon so as we know neon the atpg number of neon is 10 so that means 10 electrons are involved in neon and this is 3 s 2 and 3p 4 but we have to find the electronic configuration of sulfide ion which is s2 minus.

03:11 So this become neon and 3s2 -3p6.

03:19 All right.

03:20 So this is the electronic configuration of sulfide ion.

03:25 So in the next case we have aluminium iron.

03:34 So first we can see the electronic configuration of aluminium in the ground state.

03:38 The adequate number of aluminium is 13.

03:41 So this we can write neon and this is 3s2 3p1.

03:50 So this is also other way to represent the electronic configuration based on the noble gas.

03:59 So now in case of aluminium 3 plus ion, so that means we have to remove 3 electrons.

04:07 So these 3 electrons are removed from s np, 2 lectern are removed from s orbital and 1 from p.

04:13 So this become neon so it means we can write 1 s2 2s2 and 2p6 so in the next case we have selenium so first we see the electronic configuration of selenium so the ethnic number of selenium that is 34 so this we can write argon 3d 10 4 s2 4p4 so so now in case of selenium ion, the electronic configuration become, so organ is basically 18.

05:12 So this is 3d10, 4s2 and 4p6.

05:28 Now in the next case, we have bromide ion.

05:35 So first we see the electronic configuration of bromine...

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