Consider these elements: P, Ca, Si, S, Ga. a. Write the electron configuration for each ele

step 1 So now we'll work on problem 100 from chapter 8. In this problem, we're asked to the elements, p

Consider these elements: P, Ca, Si, S, Ga. a. Write the...

Key Concepts

Shielding and Effective Nuclear Charge

This concept involves the reduction of the full positive charge of the nucleus felt by valence electrons due to the presence of inner-shell electrons. Effective nuclear charge is a key factor in determining both the atomic radius and ionization energy, as it describes the net positive charge experienced by outer electrons and thus influences how tightly they are bound to the nucleus.

Periodic Trends – Ionization Energy

Ionization energy is the energy required to remove an electron from a neutral atom. It is influenced by factors such as nuclear charge, electron shielding, and atomic radius. Typically, ionization energy increases across a period as the electrons are held more tightly, and decreases down a group where the valence electrons are farther from the nucleus and shielded by inner electrons.

Orbital Filling and Subshell Effects

Differences in electron configurations, such as the filling of specific subshells (s, p, d, etc.), can lead to variations in chemical and physical properties among elements. These differences can affect the distribution of electrons around the nucleus, thereby influencing periodic trends like atomic size and ionization energy. Understanding the order in which orbitals are filled helps explain why trends in atomic radius and ionization energy may not always parallel each other.

Electron Configuration

This concept refers to the arrangement of electrons within the orbitals of an atom. Electron configurations are determined using principles such as the Aufbau principle, the Pauli exclusion principle, and Hund’s rule. They provide a systematic way to represent the distribution of electrons in shells and subshells, which is essential for understanding the chemical properties of elements.

Periodic Trends – Atomic Radius

Atomic radius describes the size of an atom and generally depends on the number of electron shells and the effective nuclear charge. As one moves down a group in the periodic table, additional electron shells cause the atomic radius to increase, while moving from left to right across a period generally results in a decrease in atomic radius due to increased nuclear charge pulling electrons closer.

Transcript

00:01 So now we'll work on problem 100 from chapter 8.

00:06 In this problem, we're asked to the elements, phosphorus, calcium, silicone, sulfur, and gallium.

00:15 And in part a, we're asked to write the electron configuration for each element.

00:19 So let's go ahead and start with part a.

00:24 So we first were given phosphorus, which will have noble gas configuration of neon, followed by 3s2, 3p3.

00:38 Calcium is noble gas configuration argon followed by 4s2 silicone noble gas configuration neon followed by 3s2 3p2 sulfur level gas configuration neon 3s2 3p4 and finally we have gallium which will have a noble gas configuration of argon followed by 4s2 3d10 4p1.

01:29 So now in part b, we're asked to arrange these elements in a particular way.

01:41 They want us to arrange the elements in order for decreasing atomic radius.

01:48 So the trend for atomic radius is going to increase from right to left and from top to bottom.

02:02 So the farthest to the bottom and to the right will be the largest, which we'll start with, and that's calcium.

02:08 Then this would be followed by gallium since it's farthest down of the rest.

02:14 Then it will follow the trend silicone phosphorus sulfur since those three are right next to each other and are going from right to left, left to right, and in part c we're asked to arrange the elements in order of increasing ionization energy.

02:42 Now this year, we do have a rough trend for the periodic table.

02:48 Ionization energy will increase from left to right and from bottom to top.

02:56 This one here is for atomic radius.

03:03 However, there may be some exceptions here.

03:05 For instance, calcium, we would expect to have the lowest ionization energy because it's farthest to the left.

03:16 However, gallium is actually lower, and that's because of the electron configuration.

03:21 So if we go back and look at that, we can see that gallium has an electron in the 4p orbital, which is much more easily to lose than would be the s orbital here.

03:33 So gallium is actually or sorry, the lowest.

03:41 Gallium, we're increasing, so gallium is the lowest, then followed by calcium...

Please give Ace some feedback