Question

An atom of an element has a total of 13 electrons. What is the element, and how many electrons are shown in its electron-dot structure?

Short answer

The element with 13 electrons is Aluminum (Al), and its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^1\). The electron-dot structure for Aluminum, representing its 3 valence electrons, is: . Al: :

Step-by-step solution

Find the element with 13 electrons

The element's atomic number is equal to the number of electrons in its neutral state. To find the element with 13 electrons, look up element number 13 on the periodic table: Aluminum (Al).

Determine the electron configuration of aluminum

To write the electron configuration for Aluminum, use the Aufbau principle, which states that electrons fill the lowest energy orbitals first. Use the periodic table to identify the order in which orbitals are filled: 1s2 2s2 2p6 3s2 3p1 Aluminum's electron configuration can be written as: \(1s^2 2s^2 2p^6 3s^2 3p^1\).

Create the electron-dot structure

The electron-dot structure represents the outermost electrons in the element, also referred to as the valence electrons. We only need to consider the electrons in the outermost energy level. In Aluminum's case, this corresponds to the third energy level: \(3s^2 3p^1\). There are three valence electrons in total. To create the electron-dot structure, write the element's symbol (Al) and place one dot for each valence electron around the symbol, following the order of one on each side, then two dots on one side after there is one dot on each side. The electron-dot structure for Aluminum is: . Al: :

Key concepts

Valence Electrons

Valence electrons are the electrons found in the outermost shell of an atom. They are important because they determine how an element reacts chemically with other elements.
When atoms interact to form bonds, it is these valence electrons that are either shared, lost, or gained.

For example, in the element Aluminum (Al), the valence electrons are found in the third energy level. Aluminum has an electron configuration described as \(1s^2 2s^2 2p^6 3s^2 3p^1\).

• This means there are two electrons in the 3s orbital, and one electron in the 3p orbital.
• Together, these make up Aluminum's three valence electrons.

These electrons play a key role in the element's chemical properties.

Aluminum

Aluminum is a chemical element found in group 13 of the periodic table. It is characterized by its shiny, silvery-white appearance and is known for being lightweight yet strong.
- Its atomic number is 13, meaning a neutral Aluminum atom has 13 protons and 13 electrons.
- Aluminum is widely used in the manufacture of products ranging from cans and foils to aircraft parts.

Because Aluminum easily loses its three valence electrons, it often forms bonds to create compounds such as aluminum oxide or alloys when combined with other metals.

• This characteristic makes it a versatile and valuable element in industries around the world.

Periodic Table

The periodic table is a tabular organization of chemical elements based on their atomic number, electron configuration, and recurring chemical properties. Elements are arranged in order of increasing atomic number,
and this arrangement helps to predict the properties of elements.

For example, each row in the periodic table corresponds to the filling of a specific electron shell. This allows you to easily determine an element's electron configuration.
- Aluminum, for instance, is located in the third period and group 13, indicating it is in the p-block of the periodic table with three energy levels filled.
- This systematic layout helps both in identifying elements like Aluminum and understanding their chemical behavior.

Electron-Dot Structure

The electron-dot structure, also known as the Lewis dot structure, is a simple way to represent the valence electrons of an atom or molecule. This visual representation uses dots placed around the element's symbol to show the number of valence electrons.
In the case of Aluminum, which has three valence electrons, its electron-dot structure is represented as:

• A dot on three of the four sides of the symbol \( Al \).

This method helps visualize how atoms might bond or share electrons, as electron-dot structures can combine to show molecule formation.

By indicating unpaired electrons, the electron-dot structure also helps predict the likelihood of an atom forming certain bonds. This makes it a fundamental tool in chemistry for understanding and teaching about chemical bonding.