Write the electronic configurations for the following ions:...

Key Concepts

Electronic Configuration

Electronic configuration refers to the arrangement of electrons in an atom’s or ion’s orbitals, following principles such as the Aufbau principle, Pauli exclusion principle, and Hund’s rule. This arrangement determines the chemical properties and reactivity of the species by specifying which orbitals are occupied and how many electrons are in each orbital.

Ion Formation (Cation and Anion Formation)

When atoms form ions, they either lose or gain electrons to achieve a more stable electronic configuration. Cations (positively charged ions) are formed by losing electrons, typically from the outermost shell, while anions (negatively charged ions) are formed by gaining electrons, often resulting in a configuration similar to the nearest noble gas.

Noble Gas Notation

Noble gas notation is a shorthand method used to write electronic configurations by substituting the core electrons with the symbol of the nearest noble gas in brackets. This simplifies the writing of electron configurations, especially for elements with a large number of electrons, by focusing on the valence electrons that determine chemical behavior.

Transcript

00:01 So in this video, we want to look at how to write electron configuration for some atoms or ions.

00:10 So the first one is boron with an ion in charge of 3 plus.

00:21 Right.

00:21 Buron has atomic number of 5, so if it lost three electrons, the 3 plus means it lost 3 electrons, we are loved with only 2 electrons.

00:33 Now, in writing electron configuration, we are going to use this order.

00:40 We first fill 1s before 2s, then go to 2p, 3s, and so on.

00:46 Now, s orbital takes a maximum of 2 electrons, p orbital takes a maximum of 6, d takes maximum of 10, and f takes a maximum of 14, and so on.

00:59 Right, so because burund 3 plus has only two electrons, the electron configuration will be 1s, which takes those two electrons.

01:15 So the next one, we want to look at is oxygen, which has atomic number of eight, all right? so it has gained one more electrons, so now it has nine electrons.

01:32 So the electron configuration, 1s takes two electrons, then 2s takes 2, you have 4 now, then we go to 2p, so 5 electrons remaining, so those 5 electrons will be the 2p orbital.

01:54 So 1s2, 2s2, 2p 5.

01:57 Then c, we have chlorine, 3 plus.

02:06 The atomic now of chlorine is 17.

02:09 So 3 plus means it lost 3 electrons.

02:13 So 17 minus 3, 14 electrons.

02:18 So the electron configuration will be, the electron configuration will be 1s2, 2s2, 2p6.

02:37 Now you have 10 electrons.

02:42 And then 3s would take 2.

02:46 So you have 12 now.

02:48 So two more.

02:49 Two will go to 3p.

02:51 2.