Identify the group 3A element that best fits each of the following descriptions.
(a) Has an unusually low melting point

Verified step by step guidance

1. Identify the elements in group 3A (13) of the periodic table: Boron (B), Aluminum (Al), Gallium (Ga), Indium (In), and Thallium (Tl).
2. Recall that melting point is a physical property that can vary significantly among elements in the same group.
3. Consider the general trend in melting points within group 3A: Boron has a high melting point, while the melting points of the other elements are lower.
4. Research or recall specific melting points for each element in group 3A to identify which one has an unusually low melting point.
5. Compare the melting points: Boron (high), Aluminum (moderate), Gallium (very low), Indium (moderate), Thallium (moderate).

Key Concepts

Group 3A Elements

Group 3A (or Group 13) of the periodic table includes elements such as boron, aluminum, gallium, indium, and thallium. These elements have three valence electrons and exhibit a range of physical and chemical properties. Understanding their position in the periodic table helps in predicting their behavior, including trends in melting points.

Melting Point Trends

Melting point is the temperature at which a solid becomes a liquid. In general, melting points of elements can vary significantly within a group due to differences in atomic structure and bonding. For Group 3A elements, factors such as metallic bonding and molecular structure influence their melting points, with some elements exhibiting notably low melting points.

Gallium's Unique Properties

Gallium is a notable Group 3A element that has an unusually low melting point of about 29.76 °C (85.57 °F), allowing it to melt in the palm of a hand. This property is attributed to its metallic bonding and the presence of a relatively weak crystal lattice structure. Recognizing gallium's unique characteristics is essential for identifying it in the context of the question.