Question

Write the abbreviated electron configurations for (a) Ni, (b) \(\mathrm{Cs},(\mathbf{c}) \mathrm{Ge}\) (d) \(\mathrm{Br}\), and \((\mathrm{e}) \mathrm{Bi} .\)

Short answer

[Ni]: [Ar] 4s2 3d8, [Cs]: [Xe] 6s1, [Ge]: [Ar] 4s2 3d10 4p2, [Br]: [Ar] 4s2 3d10 4p5, [Bi]: [Xe] 6s2 4f14 5d10 6p3.

Step-by-step solution

Identify Closest Noble Gas

Find the noble gas that precedes the element in the periodic table. This will serve as the starting point for the abbreviated electron configuration.

Determine Additional Electrons

Count the number of electrons added after the noble gas and determine their placement in subshells following the order of filling based on the Aufbau Principle.

Write Abbreviated Electron Configuration for Ni

For Nickel (Ni, atomic number 28), the closest noble gas is Argon (Ar, atomic number 18). After Ar, there are 10 additional electrons. The configuration after Ar is 4s2 3d8. Therefore, the abbreviated electron configuration for Ni is [Ar] 4s2 3d8.

Write Abbreviated Electron Configuration for Cs

For Cesium (Cs, atomic number 55), the closest noble gas is Xenon (Xe, atomic number 54). There is one additional electron which goes into the 6s subshell. Therefore, the abbreviated electron configuration for Cs is [Xe] 6s1.

Write Abbreviated Electron Configuration for Ge

For Germanium (Ge, atomic number 32), the closest noble gas is Argon (Ar, atomic number 18). After Ar, there are 14 additional electrons. The configuration after Ar is 4s2 3d10 4p2. Therefore, the abbreviated electron configuration for Ge is [Ar] 4s2 3d10 4p2.

Write Abbreviated Electron Configuration for Br

For Bromine (Br, atomic number 35), the closest noble gas is Argon (Ar, atomic number 18). After Ar, there are 17 additional electrons. The configuration after Ar is 4s2 3d10 4p5. Therefore, the abbreviated electron configuration for Br is [Ar] 4s2 3d10 4p5.

Write Abbreviated Electron Configuration for Bi

For Bismuth (Bi, atomic number 83), the closest noble gas is Xenon (Xe, atomic number 54). After Xe, there are 29 additional electrons. The configuration after Xe is 6s2 4f14 5d10 6p3. Therefore, the abbreviated electron configuration for Bi is [Xe] 6s2 4f14 5d10 6p3.

Key concepts

Aufbau Principle

Understanding electron configurations of atoms is crucial, and the Aufbau principle offers a fundamental rule. Imagine filling up a new building with tenants. You start from the ground floor up, right? Similarly, when we 'fill up' an atom with electrons, we start with the lowest energy levels or 'floors' and work our way up.

Electrons are naturally lazy, so they'll occupy the lowest energy subshell available before moving to the next one. Think of it like musical chairs, but the music never stops, and there are specific rules for where electrons can sit. This principle helps us predict electron configurations which play a key role in an element's chemical properties.

Noble Gas Core

The noble gas core is like a convenient shortcut when writing out an element's address in the periodic neighborhood. Just as we abbreviate street names, we can abbreviate an atom's electron configuration by starting with the closest noble gas that came before it.

Noble gases are the VIP elements of the periodic table. They have a full valence shell, making them very stable and not eager to react with others, sort of like a person who's content to stay home. Taking the noble gas's electronic structure is like saying, 'Start here, and add on whatever extra rooms needed for the new guests,' which are electrons beyond the noble gas.

Electron Subshell

Let's dive into the layers of an atom's electron city: subshells. They are the neighborhoods within the energy level zones. When electrons look for a 'home,' they choose a subshell, kind of like a family picking a neighborhood.

There are four types - s, p, d, and f. Each has a different shape and can hold a certain number of electron 'residents': s can hold 2, p can hold 6, d holds 10, and f has room for 14. Deciding where electrons live is not random; it follows rules, including the Aufbau principle, to ensure each electron finds the most energy-efficient 'residence'.

Periodic Table

The periodic table is essentially a big, organized chart of every stable and some not-so-stable atomic 'households' we know. It’s a scientist's best friend. Elements are arranged from left to right and top to bottom in order of increasing atomic number—the number of protons in the atom's 'family'.

Just as a map helps you find where you want to go, the periodic table tells us so much about the elements, like how they’ll behave, who their 'neighbors' are, and who they're related to. Having this information allows us to predict how elements will interact in reactions or predict properties of unknown elements. For instance, elements in the same column (or group) behave similarly because they have the same number of electrons in their outermost shell, influencing how they react with other elements.