Arrange the following atoms in order of increasing ionization energy: Li, K, Cr and N.

Name: Problem 32, Chapter 7: Chemistry and Chemical Reactivity
Uploaded: 2020-09-14T04:31:26-08:00
Duration: 5 min 19 s
Channel: Elaine Velicaria
Description: Arrange the following atoms in order of increasing ionization energy: Li, K, Cr and N.

Arrange the following atoms in order of increasing...

Key Concepts

Electron Shielding

Electron shielding is the phenomenon where inner electrons partially obstruct the attractive force of the nucleus on the outer electrons. Greater shielding typically results in lower ionization energy, as the outer electrons are less tightly held by the nucleus.

Effective Nuclear Charge

Effective nuclear charge is the net positive charge experienced by an atom's valence electrons after accounting for electron shielding by inner electrons. It plays a major role in determining how tightly electrons are held and thus influences the ionization energy.

Periodic Trends

Periodic trends refer to systematic variations in elemental properties across the periodic table. For ionization energy, the trend generally shows an increase from left to right across a period and a decrease down a group, which helps predict and compare the energy required for electron removal.

Ionization Energy

Ionization energy is the energy required to remove an electron from a neutral atom in the gaseous state. It indicates how strongly an atom holds on to its electrons and is a key factor in understanding an element’s chemical reactivity.

Transcript

00:01 Alright, for this problem, we are asked to put these elements, lithium, potassium, chromium, and nitrogen in increasing order, depending on their ionization energy.

00:15 But before we do that, let's first review what ionization energy is and how an element's nuclear charge relates to it.

00:23 So ionization energy, or which i will abbreviate i .e., refers to the amount of energy, so amount of energy that we need to remove an electron from an atom, which is related to an element's nuclear charge.

01:01 So to recap, the nuclear charge refers to the strength of attraction force between an atom's nucleus and the electrons surrounding it.

01:10 That is to say that if we have a high nuclear charge, which i abbreviated as nc, the stronger attraction there will be between the nucleus and the electrons.

01:27 Attraction.

01:33 And similarly, if we have a low nuclear charge, the weaker attraction there is between the nucleus and the electrons.

01:42 So based on this idea, we can deduce that it will be easier to remove the electrons that are weakly stabilized by the nucleus, thus lower ionization energy is required.

01:56 As compared to those that have a strong attraction, with the nucleus which will require a much higher energy so higher i'm going to move this on the slide real quick higher energy and i just want to remind you that a nuclear charge increases as you go across a row of the periodic table okay so with this in mind let's go back and look at the following elements.

02:36 Both lithium and potassium are group a, group 1a elements.

02:44 Nitrogen is a group 5a element, while chromium is a group 6b element.

02:54 So although potassium and lithium are in the same group, potassium has a higher principal quantum energy.

03:02 Remember that potassium has n equals 4, while lithium has n equals 2...

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