Problem 13 - Chemistry: The Central Science in SI Units, Global Edition

Question

Write the Lewis symbol for atoms of each of the following elements: \((\mathbf{a}) \mathrm{Te},(\mathbf{b}) \mathrm{Si},(\mathbf{c}) \mathrm{Kr},(\mathbf{d}) {\mathrm{P}}\).

Step-by-Step Solution

Answer

The Lewis symbols for the given elements are as follows: (a) \(\mathrm{Te}\) (Tellurium): \(\cdot\!\!\!\;\stackrel{\big\circ}{Te}\!\!\!\cdot\!\!\!\, \;/\!/ \!\!\!\!\!\!\!\! \cdot \) (b) \(\mathrm{Si}\) (Silicon): \(\;/\!/ \;\stackrel{\big\circ}{Si}\;/ \!/ \) (c) \(\mathrm{Kr}\) (Krypton): \(\cdot\!\!\!\;\stackrel{\big\circ}{Kr}\!\!\!\!\!\!\!\! \cdot\! \!/ \!/ \!/ \!/ \!/ \!/ \!/ \!/ \) (d) \(\mathrm{P}\) (Phosphorus): \(\;\stackrel{\big\circ}{P}\!\!\!\!\!\!\!\! \cdot\!-\!\!\!\;\!\!\!\!/\"/>\!\!\!\!/ \)

Step 1: Find the Electron Configuration for Each Element

First, we need to find the electron configurations of each of the given elements using the periodic table.

Step 2: Determine the Valence Electrons

We will determine the valence electrons for each element based on its electron configuration. Valence electrons are the electrons in an atom's outermost shell.

Step 3: Draw the Lewis Symbol for Each Element

A Lewis symbol is a representation of the element symbol surrounded by dots representing the valence electrons. Now, we will draw the Lewis symbols for each of the elements. For element (a) \(\mathrm{Te}\) (Tellurium): Tellurium is in Group 16, Period 5 of the periodic table, so it has an electron configuration of [Kr]5s²4d¹⁰5p⁴. Valence electrons: 5s²5p⁴ = 6 Lewis Symbol: \(\cdot\!\!\!\;\stackrel{\big\circ}{Te}\!\!\!\cdot\!\!\!\, \;/\!/ \!\!\!\!\!\!\!\! \cdot \) For element (b) \(\mathrm{Si}\) (Silicon): Silicon is in Group 14, Period 3 of the periodic table, so it has an electron configuration of [Ne]3s²3p². Valence electrons: 3s²3p² = 4 Lewis Symbol: \(\;/\!/ \;\stackrel{\big\circ}{Si}\;/ \!/ \) For element (c) \(\mathrm{Kr}\) (Krypton): Krypton is in Group 18, Period 4 of the periodic table, so it has an electron configuration of [Ar]4s²3d¹⁰4p⁶. Valence electrons: 4s²4p⁶ = 8 Lewis Symbol: \(\cdot\!\!\!\;\stackrel{\big\circ}{Kr}\!\!\!\!\!\!\!\! \cdot\! \!/ \!/ \!/ \!/ \!/ \!/ \!/ \!/ \) For element (d) \(\mathrm{P}\) (Phosphorus): Phosphorus is in Group 15, Period 3 of the periodic table, so it has an electron configuration of [Ne]3s²3p³. Valence electrons: 3s²3p³ = 5 Lewis Symbol: \(\;\stackrel{\big\circ}{P}\!\!\!\!\!\!\!\! \cdot\!-\!\!\!\;\!\!\!\!/\"/>\!\!\!\!/ \)

Key Concepts

Electron Configuration

Every element has a unique electron configuration, which describes the arrangement of electrons in the atom's orbitals. The electron configuration can be determined using the periodic table, and it follows a specific order based on the increasing atomic number and energy level. Here's how you can decipher it:

• Electrons fill orbitals in a fixed sequence: starting in the lowest energy level (closest to the nucleus) and moving outward.
• The sequence of filling is typically: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, and so on.
• This order is governed by the Aufbau principle, along with Hund's rule and Pauli exclusion principle.

For instance, the electron configuration for Tellurium is \([Kr]5s^24d^{10}5p^4\), meaning it has a chemical environment similar to Krypton but with additional electrons distributed into higher orbitals. Understanding electron configurations is crucial for predicting chemical behavior and interactions between elements.

Valence Electrons

Valence electrons are the electrons located in the outermost shell of an atom. They play a crucial role in chemical reactions and bonding.

• These electrons are typically found in the outermost s and p orbitals.
• The number of valence electrons determines an element's reactivity and its ability to bond with other elements.

For example: - Tellurium (Te), with an electron configuration of [Kr]5s²4d¹⁰5p⁴, possesses 6 valence electrons. - Silicon (Si), with [Ne]3s²3p², has 4 valence electrons. - Krypton (Kr), being a noble gas, has a complete outer shell with 8 valence electrons. - Phosphorus (P) has 5 valence electrons from its [Ne]3s²3p³ configuration. Understanding valence electrons helps predict how an element will interact with others, and it’s key in drawing Lewis symbols.

Periodic Table

The periodic table is a powerful tool that organizes all known elements based on their atomic number and properties. It's structured in such a way that elements with similar characteristics are arranged in the same column or group.

• Rows are called periods and signify increasing energy levels.
• Columns are called groups and indicate elements with similar chemical and physical properties.

This arrangement allows for easy determination of electron configurations and valence electrons by observing an element's position. - For example, Tellurium (Te) is found in Group 16 and Period 5, suggesting it has similar properties to other chalcogens. - Silicon (Si) in Group 14 and Period 3 is similar to other carbon-group elements. In essence, the periodic table not only helps us sort elements but also to predict their behaviors and interactions.

Element Groups

Elements are divided into groups within the periodic table based on shared properties. Each group shares a common number of valence electrons among its elements, which gives these groups their characteristic traits and behaviors.

• Group 1 elements have 1 valence electron and are known as alkali metals.
• Group 18 elements, like Krypton, are noble gases and are noted for their full valence shell of 8 electrons, rendering them largely unreactive.
• Groups between 1 and 18 exhibit varying properties that gradually change across periods.

When examining elements: - Tellurium (Te) in Group 16 has 6 valence electrons, showing reactive properties typical of this group. - Silicon (Si) in Group 14 displays semiconductive properties essential to electronics. Understanding these groups allows for predictions of elemental interactions and is fundamental in writing Lewis symbols, which visually portray the valence electrons.