Problem 8 - Chemistry and Chemical Reactivity

Question

Titanium and thallium have symbols that are easily confused with each other. Give the symbol, atomic number, atomic weight, and group and period number of each element. Are they metals, metalloids, or nonmetals?

Step-by-Step Solution

Answer

Titanium (Ti) - Atomic Number: 22, Atomic Weight: 47.87, Group 4, Period 4, Metal. Thallium (Tl) - Atomic Number: 81, Atomic Weight: 204.38, Group 13, Period 6, Metal.

Step 1: Identify the Symbols

Titanium has the chemical symbol \( \text{Ti} \), while thallium has the symbol \( \text{Tl} \). It is important not to confuse these symbols, as they represent different elements.

Step 2: Determine the Atomic Numbers

Titanium has an atomic number of 22. Thallium has an atomic number of 81. The atomic number indicates the number of protons in the nucleus of an atom of the element.

Step 3: Locate the Atomic Weights

Titanium has an atomic weight of approximately 47.87 u. Thallium has an atomic weight of approximately 204.38 u. Atomic weight is the average mass of atoms of an element.

Step 4: Identify Group and Period Numbers

Titanium is located in Group 4 and Period 4 of the periodic table. Thallium is located in Group 13 and Period 6. The group number indicates the column of the periodic table, and the period number indicates the row.

Step 5: Determine Metal, Metalloid, or Nonmetal

Titanium is a metal and is known for its strength and low density. Thallium is also a metal and is known for its softness and toxicity.

Key Concepts

Chemical Symbols

In the Periodic Table, each element is represented by a unique chemical symbol. These symbols consist of one or two letters, where the first letter is always capitalized and the second, if present, is lowercase. The chemical symbol is a shorthand way of referring to an element, making it easier to write chemical equations and identify substances.

• Example 1: Titanium is represented by the symbol \( \text{Ti} \).
• Example 2: Thallium uses the symbol \( \text{Tl} \).

While these symbols are concise, it's important to memorize them as certain elements can be easily confused—such as Titanium and Thallium. Misunderstanding could lead to errors in experiments and chemical calculations.

Atomic Number

An element’s atomic number is fundamental to its identity. It represents the number of protons in the nucleus of an atom of the element. Thus, each element has a unique atomic number.

• Titanium (\( \text{Ti} \)): Atomic number is 22.
• Thallium (\( \text{Tl} \)): Atomic number is 81.

The atomic number also determines the element's position in the Periodic Table, which is arranged in order of increasing atomic numbers. This ordering is crucial for understanding elements' properties and behaviors. For example, knowing that Titanium has an atomic number of 22 tells us it will be the 22nd element in the Table, providing insights into its chemical profile and how it might interact with other elements.

Atomic Weight

The atomic weight of an element is an average of the masses of its isotopes, weighted according to their natural abundance. It is measured in atomic mass units (u), where 1 u is defined as one-twelfth the mass of a carbon-12 atom.

• Titanium (\( \text{Ti} \)): Atomic weight is around 47.87 u.
• Thallium (\( \text{Tl} \)): Atomic weight is approximately 204.38 u.

Atomic weight helps us understand an element’s mass on average, which is critical for calculations in chemistry, such as determining how much of an element is needed in a reaction. It can also influence the physical properties of the element, such as density. Despite similar symbols, Titanium and Thallium have significantly different atomic weights, affecting how they might be used in practical applications.

Element Classification

Elements in the Periodic Table are classified into categories such as metals, metalloids, and nonmetals based on their distinct characteristics. These classifications help us predict their behavior and uses.

• Metals: Typically shiny, conductive, and malleable. Titanium and Thallium fall into this category.
• Metalloids: Have properties in between metals and nonmetals.
• Nonmetals: Typically not conductive, not malleable, and not shiny.

Titanium is prized for its strength and low density, making it ideal for aerospace applications. Thallium, though also a metal, is soft and toxic, being used in specialized electronic equipment. Understanding an element's classification aids in determining its uses and how it might react in different conditions. Additionally, knowing the group and period numbers, such as Group 4, Period 4 for Titanium, and Group 13, Period 6 for Thallium, helps locate these elements quickly in the table as it indicates their row and column positions.