Question

Which two of the following elements would you expect to be most similar to each other? Why? \(\mathrm{Mg}, \mathrm{N}, \mathrm{F}, \mathrm{S}, \mathrm{Ne}, \mathrm{Ca}\)

Short answer

Magnesium (Mg) and Calcium (Ca) would be the most similar to each other because they are both in group 2 of the Periodic Table, which means they share similar chemical properties as alkaline earth metals.

Step-by-step solution

Understand the Periodic Table

Identify the position of each given element on the Periodic Table. Elements are arranged in order of increasing atomic number and are grouped into periods (horizontal rows) and groups/families (vertical columns). Elements in the same group have similar chemical properties because they have the same number of valence electrons.

Determine Group and Period

Find the group and period for each element: - Magnesium (Mg) is in group 2 and period 3.- Nitrogen (N) is in group 15 and period 2.- Fluorine (F) is in group 17 and period 2.- Sulfur (S) is in group 16 and period 3.- Neon (Ne) is in group 18 and period 2.- Calcium (Ca) is in group 2 and period 4.

Compare Elements

Compare elements to determine which ones are most similar based on their groupings. Group 2 contains the alkaline earth metals, and both Mg and Ca are in this group, though in different periods. This similarity in group means that they will have very similar chemical properties because they both have two valence electrons.

Key concepts

Chemical Properties and the Periodic Table

Exploring the periodic table helps us understand how elements are connected to one another through their fundamental characteristics. Chemical properties describe how a substance interacts with other substances, such as its reactivity or bonding capacity. A key factor determining chemical properties is the element's group on the periodic table.

For example, consider the exercise where we needed to identify similarities among selected elements. Grouping them based on their position in the periodic table, we could infer their chemical properties. Since magnesium (Mg) and calcium (Ca) belong to the same group, known as the alkaline earth metals, they exhibit parallel behaviors such as similar reactions with water, generating hydroxides, and releasing hydrogen gas.
Moreover, they both readily form ionic compounds by losing two electrons, showing how group placement influences chemical properties.

The Role of Valence Electrons

Valence electrons play a pivotal role in dictating an element's reactivity and bonding, serving as a foundation for chemical properties. These electrons are situated in the outermost shell of an atom and are involved in forming chemical bonds.

Regarding our exercise, magnesium (Mg) and calcium (Ca) each have two valence electrons since they are situated in group 2 of the periodic table. This commonality is what gives rise to their shared chemical characteristics. Valence electrons are the primary reason why elements within the same group have analogous chemical reactivities and why they often form bonds in a predictable manner, establishing stable electronic configurations through the loss, gain, or sharing of these outer electrons.

Understanding Alkaline Earth Metals

Alkaline earth metals, residing in group 2 of the periodic table, include elements like beryllium (Be), magnesium (Mg), and calcium (Ca). They are distinguished by their two valence electrons, which they tend to lose when reacting, forming +2 ions. This category of metals boasts moderate reactivity, which is lesser than their group 1 counterparts— the alkali metals.

From the textbook exercise, we can conclude that magnesium (Mg) and calcium (Ca), being alkaline earth metals, share noteworthy similarities in their physical and chemical properties. These include their reactions to form oxides, their characteristic flame colors upon burning, and their tendencies to form compounds with similar stoichiometries.