Problem 52 - General Chemistry: Principles and Modern Applications

Question

Refer to the periodic table inside the front cover and identify (a) the element that is in group 11 and the sixth period (b) an element with atomic number greater than 50 that has properties similar to the element with atomic number 18 (c) the group number of an element \(\mathrm{E}\) that forms an ion \(\mathrm{E}^{2-}\) (d) an element \(M\) that you would expect to form the ion \(\mathrm{M}^{3+}\)

Step-by-Step Solution

Answer

a) The element in Group 11 and the sixth period is Gold (Au). b) An element with atomic number greater than 50 that has similar properties to Argon is Xenon (Xe). c) The element E that forms an Ion \( \mathrm{E}^{2-} \) is from Group 16. d) The element M that forms an Ion \( \mathrm{M}^{3+} \) is from Group 13.

Step 1: Identify the Element in Group 11 and Sixth Period

Group 11 of the periodic table consists of the transition metals; copper (Cu), silver (Ag), gold (Au), and roentgenium (Rg). The sixth period specifies the row, so it is Au (Gold).

Step 2: Find an Element Similar to Atomic Number 18 but Greater Than 50

The element with atomic number 18 is Argon, a noble gas. Elements within the same group share similar properties due to having the same number of electrons in their outermost shell. Looking for an element with an atomic number greater than 50, in the same group (Group 18), we find Xenon (Xe).

Step 3: Determine the Group Number of Element E

Element E forms an ion \( \mathrm{E}^{2-} \), which means that it gains 2 electrons to achieve greater stability. This is typical behavior for elements in the 16th group of the periodic table, which includes Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te), and Polonium (Po). So, E belongs to Group 16.

Step 4: Identify an Element M That is Expected to form \( \mathrm{M}^{3+} \)

Ion \( \mathrm{M}^{3+} \) means that M loses 3 electrons. Elements in the 13th group of the periodic table form +3 ions because they have 3 electrons in their outer shell that they can lose to achieve stability. Examples are Aluminium (Al), Gallium (Ga), Indium (In), and Thallium (Tl). So, M is a member of Group 13.

Key Concepts

Group 11 Elements

In the periodic table, Group 11 consists of precious metals that are commonly known for their excellent conductivity and malleability. The elements in this group include copper (Cu), silver (Ag), gold (Au), and roentgenium (Rg). These elements are often categorized as transition metals. They are highly valued both for industrial applications and their economic worth, particularly gold and silver.

Group 11 elements are located in different periods, but when focusing on the sixth period, the element in question is gold (Au). Gold not only stands out for its lustrous appearance and resistance to tarnish, but it also has significant relevance in electronics and jewelry. Its presence in the sixth period denotes that it has a larger atomic size compared to copper and silver due to the additional electron shells.

These elements share some typical characteristics:

• They have one electron in their outermost shell.
• They are excellent conductors of electricity and heat.
• They exhibit high levels of malleability and ductility.
• They form alloys easily with other metals.

Understanding the properties of Group 11 elements helps in appreciating their roles in various technological and economic fields.

Noble Gases

Noble gases are located in Group 18 of the periodic table. They are called "noble" because of their lack of reactivity under normal conditions, which makes them "inert." These gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). The lack of reactivity is due to their full valence electron shell, granting them maximum stability.

Argon, with atomic number 18, is the first heavier noble gas. For an element with a larger atomic number but similar properties as argon, we look at xenon (Xe), which is in the same group. Xenon, like other noble gases, is colorless, odorless, and non-flammable. Despite their lack of reactivity, some noble gases, particularly xenon, can form compounds under special conditions.

Key characteristics of noble gases are:

• They are colorless, odorless gases at room temperature.
• They exhibit very low chemical reactivity.
• They have complete valence electron shells.
• They are used in various fields, such as lighting, welding, and as inert environments for chemical reactions.

Noble gases play integral roles in scientific applications due to their stability and non-reactive nature.

Ion Formation

Ion formation is a process where atoms gain or lose electrons to become more stable, achieving a full valence shell configuration similar to noble gases. This often involves elements from different groups in the periodic table, which form ions depending on their placement.

For instance, elements in Group 16, such as oxygen (O), sulfur (S), and selenium (Se), tend to gain two electrons to form a stable \( E^{2-} \) ion. This behavior is driven by their need to complete their valence shell, resulting in negative ions.

On the other hand, elements in Group 13, like aluminum (Al) and gallium (Ga), often lose three electrons forming \( M^{3+} \) ions to fulfill their requirement for stability. Their electronic structure allows them to shed the extra electrons more easily, resulting in positively charged ions.

The process of ion formation can be summarized by:

• Ions form to achieve electronic configurations similar to noble gases.
• Loss of electrons leads to positive ions (cations), while gaining electrons results in negative ions (anions).
• The group number of an element often indicates the common ion formation behavior.

Understanding ion formation is crucial in studying reactions and bonding in chemistry.

Period 6 Elements

Elements in the sixth period of the periodic table have a rich variety and include both metals and non-metals. This period starts at cesium (Cs) and ends with radon (Rn), covering a wide span of elements. These elements have three filled inner electron shells and an increasing number of valence electrons as one moves from left to right across the period.

As we progress through this period, the elements usually exhibit heavy and dense characteristics. This is because, as the atomic number increases, more protons and neutrons are added to the nucleus, making the atoms larger and heavier. Gold (Au), a member of Group 11, belongs to this period, showcasing the common trait of sizable, robust atomic structures with significant electron shielding.

Notable aspects of Period 6 elements include:

• They cover both transition metals and post-transition metals.
• These elements tend to have high atomic masses.
• Their atomic radii increase notably compared to elements in preceding periods.
• Periods account for more complex electron configurations, contributing to diverse chemical properties.

Exploring Period 6 gives insight into various complex and fascinating elements with extensive applications in multiple industries.