Problem 57 - Chemistry and Chemical Reactivity

Question

Specify the number of valence electrons for \(\mathrm{Li}, \mathrm{Ti}, \mathrm{Zn}\) Si, and Cl.

Step-by-Step Solution

Answer

Li: 1, Ti: 4, Zn: 2, Si: 4, Cl: 7 valence electrons.

Step 1: Understanding Valence Electrons

Valence electrons are the electrons in the outermost shell of an atom. These electrons play a key role in chemical bonding and properties of elements. To find the number of valence electrons, we look at the element's group number in the periodic table.

Step 2: Lithium (Li)

Lithium is in group 1 of the periodic table. Elements in group 1 have 1 valence electron. Thus, Li has 1 valence electron.

Step 3: Titanium (Ti)

Titanium is in group 4 of the periodic table. Transition metals like Ti can have valence electrons in both their outermost and penultimate shells. For Ti, it typically uses its 4 outer electrons in bonds, so it is considered to have 4 valence electrons.

Step 4: Zinc (Zn)

Zinc is in group 12 of the periodic table and is a transition metal. It is commonly considered to have 2 valence electrons in its 4s subshell.

Step 5: Silicon (Si)

Silicon is located in group 14 of the periodic table. Elements in group 14 have 4 valence electrons. Therefore, Si has 4 valence electrons.

Step 6: Chlorine (Cl)

Chlorine is in group 17, also known as the halogens. Elements in group 17 have 7 valence electrons. Therefore, Cl has 7 valence electrons.

Key Concepts

Periodic Table

The periodic table is a comprehensive chart that organizes the chemical elements based on their atomic number, electron configuration, and recurring chemical properties. It is structured in a way that elements in the same column, called groups, share similar characteristics. The position of an element on the periodic table is crucial in determining its chemical behavior and bonding properties.

Each group of elements has a specific number of valence electrons, which are the electrons in the outermost shell of an atom. For instance, elements in Group 1, such as Lithium (Li), have one valence electron. On the other hand, elements in Group 14, like Silicon (Si), possess four valence electrons. The periodic table helps predict how an element will react in chemical bonding based on its valence electrons.

To quickly find how many valence electrons an element has, check its group number. This handy guide makes the periodic table an essential tool for chemists to understand element interactions.

Chemical Bonding

Chemical bonding refers to the forces that hold atoms together to form molecules and compounds. These bonds are primarily due to the interactions between valence electrons of atoms. Understanding how these electrons participate in bonding is key to predicting the properties of a compound.

There are several types of chemical bonds:

• Ionic bonds: Formed through the transfer of valence electrons from one atom to another, typically between metals and nonmetals.
• Covalent bonds: Occur when atoms share valence electrons to achieve a full outer shell, common among nonmetals.
• Metallic bonds: Involve the pooling or sharing of electrons among a network of metal atoms, leading to properties like conductivity and malleability.

Valence electrons are fundamental in determining the type and strength of chemical bonds formed. For example, Titanium (Ti), which is often used in its metallic form, can share its valence electrons to create strong metallic bonds.

Transition Metals

Transition metals are found in the middle section of the periodic table, specifically groups 3 through 12. These elements are characterized by their ability to use the electrons in their outermost and next-to-outermost shells for bonding, which often results in complex chemical behaviors.

Unlike main-group elements, the number of valence electrons for transition metals isn't as straightforward. For instance, Zinc (Zn) is typically considered to have two valence electrons, which are located in its 4s orbital.

Transition metals such as Titanium (Ti) are versatile in their bonding capabilities due to their electron configurations. This flexibility allows them to form various oxidation states and complex compounds. This makes them invaluable in industries ranging from electronics to jewelry, due to their diverse chemical properties and robust bonding abilities.