Question

How many single bonds are typically formed by the following atoms? (a) \(\mathrm{H}\) (b) \(\mathrm{N}\) (c) \(\mathrm{F}\) (d) \(\mathrm{Ne}\)

Short answer

Hydrogen typically forms 1 single covalent bond, Nitrogen typically forms 3 single covalent bonds, Fluorine typically forms 1 single covalent bond, and Neon does not typically form any bonds.

Step-by-step solution

Determine Valence Electrons for Hydrogen

Hydrogen (H) is in group 1 of the periodic table and therefore has 1 valence electron. Since it has a single valence electron, it can form one single covalent bond.

Determine Valence Electrons for Nitrogen

Nitrogen (N) is in group 15 of the periodic table and therefore has 5 valence electrons. Nitrogen can form three single covalent bonds by sharing three of its valence electrons.

Determine Valence Electrons for Fluorine

Fluorine (F) is in group 17 of the periodic table and therefore has 7 valence electrons. Fluorine can form one single covalent bond by sharing one of its valence electrons.

Determine Valence Electrons for Neon

Neon (Ne) is in group 18 of the periodic table and therefore has 8 valence electrons. However, Neon is a noble gas and it has a complete octet already. Hence, it does not typically form any single covalent bonds.

Key concepts

Valence Electrons

Valence electrons are the electrons located in an atom's outermost shell. They play a crucial role in determining how an atom will interact with other atoms. Elements tend to react in ways that allow them to achieve a full outer shell, similar to the stable configuration of noble gases. The number of valence electrons helps predict the type and number of bonds an atom can form. For example:

• Hydrogen has 1 valence electron, which allows it to form one single covalent bond to achieve a helium-like configuration.
• Nitrogen, having 5 valence electrons, tends to form 3 covalent bonds to reach the stable configuration of a noble gas, neon.
• Fluorine, with 7 valence electrons, typically forms one bond to complete its octet.

As you can see, understanding valence electrons is key to predicting bonding behavior and molecule formation.

Periodic Table

The periodic table is an organized chart of elements, arranged by increasing atomic number, and it predicts the properties of elements based on their position. The elements are placed in rows and columns that highlight periodic trends such as electronegativity, atomic radius, and ionization energy. The table is divided into groups (vertical columns) and periods (horizontal rows). Each group contains elements with the same number of valence electrons, meaning they exhibit similar chemical behavior. For instance:

• Group 1 elements, like hydrogen, have 1 valence electron.
• Group 15 elements, such as nitrogen, contain 5 valence electrons.
• Group 17 elements, including fluorine, are characterized by 7 valence electrons.
• Noble gases, found in Group 18, possess 8 valence electrons, except helium which has 2.

Learning the structure of the periodic table helps you quickly deduce the chemical tendencies of different elements.

Noble Gases

Noble gases are a group of elements characterized by their complete valence shell, making them largely unreactive under standard conditions. They are located in Group 18 of the periodic table and include helium, neon, argon, krypton, xenon, and radon. These gases have the maximum number of valence electrons that their outer shell can hold, which is generally eight (octet), except for helium that has two. This stable electronic configuration means that noble gases:

• Rarely form compounds, because they do not need to gain, lose, or share electrons to achieve stability.
• Exhibit very low chemical reactivity, which is why neon, for instance, does not tend to form covalent bonds as other elements might.
• Are used in applications requiring inert atmospheres, such as neon lights or argon-filled light bulbs.

Their stability showcases the importance of atomic electron configuration in determining an element's chemical behavior.