Write electron configurations for the most stable ion formed...

Key Concepts

Electron Configuration

Electron configuration refers to the arrangement of electrons in the orbitals of an atom or ion. This concept is governed by principles such as the Aufbau principle, Hund's rule, and the Pauli exclusion principle, which together dictate the order in which orbitals are filled. Understanding electron configuration is essential for predicting chemical behavior and reactivity.

Ion Formation

Ion formation involves the gain or loss of electrons to form charged particles (ions) in order to achieve a more stable electron arrangement, typically one that resembles the electron configuration of a noble gas. In ionic compounds, atoms form ions by either losing electrons to form cations or gaining electrons to form anions.

Noble Gas Configuration

Noble gas configuration is a stable electron arrangement in which an atom or ion has a complete valence shell, similar to the inert gases found in Group 18 of the periodic table. This stability is often the driving force behind electron transfer during the formation of ions in ionic compounds.

Periodic Trends in Ion Stability

Periodic trends such as electronegativity, ionization energy, and atomic radius influence the tendency of elements to either lose or gain electrons. These trends help predict the most stable ionic forms of elements, as atoms tend to form ions that lead to a lower energy, more stable electron configuration, often resembling that of a noble gas.

Transcript

00:01 So in this video we're going to talk about question 46 from chapter 8, which says write electron configurations for the most stable ion formed by each of the elements, tellurium, chlorine, strontium, and lithium when in stable ionic compounds.

00:14 So two things to keep in mind.

00:17 So how are we going to determine what ion we are going to form from these atoms? will atoms like to gain or lose electrons to form ions so that they have the same electron configuration as the noble gases? so whatever noble gas it's nearest to, we just figure out how many electrons we need to gain or lose to get there, and that'll be the charge.

00:37 And then another thing that we can use to make this easier is we can abbreviate part of the electron configurations for an element or ion by writing the noble gas that comes before it.

00:47 So if an element or ion comes after a noble gas in the periodic table, then you can write the noble gas in brackets and then continue to write the electron configuration.

00:59 With that noble gas just standing for the configuration of that noble gas.

01:05 So for tellurium, how do we know what ion tellurium is going to want to form? well, if we look at the periodic table, tellurium is right here, and the closest noble gas is xenon, which is just two electrons away.

01:18 So tellurium is going to gain two electrons in order to have the more stable electronic configuration of xenon.

01:24 So we're going to form tellurium minus two.

01:27 And then what's the electronic configuration? well, we know we can abbreviate it using the noble gas that comes before it, so that's going to be krypton.

01:38 And i actually forgot to write it here.

01:40 So before this, we write krypton.

01:44 And then what comes after krypton? well, after krypton, we're going to fill our 5s orbital, and then our 4d orbital, and then our 5p orbital.

01:57 So 4d10, we put 10 electrons in our 4d orbital.

02:00 We put two electrons in our 5s orbital, and then we put 6 electrons in our 5p orbital.

02:06 Remember, we have two more electrons than normal, so it's not 5p4, it's 5p6.

02:16 Next we have chlorine.

02:17 So what ion does chlorine like to form? well, chlorines right here, and the closest noble gas is argon, and that's just one electron away.

02:25 So chlorine is going to gain one electron.

02:28 It's going to have a minus one charge.

02:30 So we're talking about the ion with the minus one charge, chloride, minus one.

02:35 So what noble gas comes before that? well, we're going to abbreviate everything that's neon and before neon using neon in brackets.

02:44 So we have neon.

02:46 And then what comes after neon? well, after neon, we start the next row.

02:49 We fill our 3s orbital with two electrons...

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