Question

Give the name and symbol or formula of a Group \(3 \mathrm{~A}(13)\) element or compound that fits each description or use: (a) Component of heat-resistant (Pyrex-type) glass (b) Largest temperature range for liquid state of an element (c) Elemental substance with three-center, two-electron bonds (d) Metal protected from oxidation by adherent oxide coat (e) Toxic metal that lies between two other toxic metals.

Short answer

(a) Boron (B), (b) Gallium (Ga), (c) Boron (B), (d) Aluminum (Al), (e) Thallium (Tl)

Step-by-step solution

Identify Elements in Group 3A(13)

Group 3A(13) elements in the periodic table include Boron (B), Aluminum (Al), Gallium (Ga), Indium (In), and Thallium (Tl).

(a) Component of heat-resistant (Pyrex-type) glass

Pyrex glass is composed mainly of borosilicate. The element in Group 3A(13) used in Pyrex glass is Boron (B).

(b) Largest temperature range for liquid state of an element

Gallium (Ga) has the largest temperature range for its liquid state among the Group 3A(13) elements. It melts at 29.76°C and boils at 2204°C.

(c) Elemental substance with three-center, two-electron bonds

Boron (B) forms three-center, two-electron bonds, particularly in boranes.

(d) Metal protected from oxidation by adherent oxide coat

Aluminum (Al) is protected from oxidation by an adherent oxide layer that forms on its surface.

(e) Toxic metal that lies between two other toxic metals

Thallium (Tl) is a toxic metal in Group 3A(13). It lies between Lead (Pb) and Mercury (Hg) on the periodic table, both of which are also toxic.

Key concepts

Pyrex glass composition

Pyrex glass is well-known for its heat-resistant properties. This makes it ideal for cookware and laboratory glassware. The key component that gives Pyrex its unique qualities is boron (B). Boron is a Group 3A (13) element, and when it is combined with silica (SiO2), it forms borosilicate glass.
Borosilicate glass has a low coefficient of thermal expansion, meaning it does not expand much when heated. This makes it very resistant to thermal shock, which is why you can take a Pyrex dish from the freezer directly into a hot oven without breaking it. The presence of boron allows the glass to better withstand rapid temperature changes.
This composition is vital in making durable and reliable glassware for multiple applications.

Gallium liquid state range

Gallium (Ga) is a fascinating metal that is part of Group 3A (13). One of its most interesting properties is its extremely wide liquid state temperature range. Gallium melts at just 29.76°C, which means it can melt in your hand due to body heat. However, it does not boil until it reaches a scorching 2204°C.
This wide liquid range makes gallium useful in high-temperature thermometry and in creating high-performance alloys. Additionally, gallium's ability to remain liquid over such a wide temperature range makes it useful in electronics, particularly in semiconductors and LEDs. Handling gallium can be very interesting because you can see it transition between solid and liquid states at such manageable temperatures.

three-center two-electron bonds

Boron (B) is unique in that it can form three-center, two-electron bonds. These types of bonds are particularly seen in compounds known as boranes. In boranes, electrons are shared between three atoms instead of the usual two.
This type of bonding results in structures that are stable yet quite different from those observed in typical covalent bonding. These bonds are significant in the field of chemistry because they help explain the stability and structure of boron-containing compounds. Understanding three-center, two-electron bonds helps chemists design new molecules and materials that could have unique properties.

Aluminum oxidation protection

Aluminum (Al) is a widely used metal because of its lightweight and strong properties. But, one of its most important features is its resistance to corrosion. When aluminum is exposed to air, it rapidly forms a thin layer of aluminum oxide (Al2O3) on its surface.
This oxide layer is very adherent and protects the underlying metal from further oxidation. This means that aluminum can be used in a variety of applications without rusting or corroding easily. This property is especially useful in construction, automotive, and aerospace industries, where long-term exposure to the elements is a concern.

Thallium toxicity

Thallium (Tl) is a heavy metal found in Group 3A (13) that is highly toxic to humans. It sits between lead (Pb) and mercury (Hg) on the periodic table, which are also well-known toxic metals.
Thallium was historically used in rat poisons and insecticides, but its use has declined due to safety concerns. Exposure to thallium, even in small amounts, can lead to serious health issues including hair loss, nerve damage, and even death. Because of its toxicity, handling thallium requires strict safety measures to prevent accidental poisoning. Understanding the dangers of thallium is crucial for anyone who might encounter it in a laboratory or industrial setting.