At room temperature, a certain element is a colorless, unre-active gas. Is the element likely to be a metal, a nonmetal, or a semimetal?

Verified step by step guidance

1. Identify the physical and chemical properties described: The element is a colorless, unreactive gas at room temperature.
2. Consider the general properties of metals, nonmetals, and semimetals (metalloids). Metals are typically solid at room temperature (except mercury) and are reactive. Semimetals can be solid or less commonly gaseous and show varying reactivity.
3. Focus on nonmetals, which often include gases at room temperature and can range from reactive to unreactive.
4. Recall that noble gases are a group of nonmetals that are colorless, odorless, and very unreactive due to their stable electron configurations.
5. Conclude that the element described is likely a nonmetal, specifically a noble gas, based on its described properties of being a colorless and unreactive gas at room temperature.

Key Concepts

Properties of Metals, Nonmetals, and Semimetals

Metals are typically shiny, conductive, and malleable, while nonmetals are often dull, insulative, and brittle. Semimetals, or metalloids, exhibit properties of both metals and nonmetals. Understanding these characteristics helps in classifying elements based on their physical and chemical behaviors.

States of Matter and Gaseous Elements

At room temperature, elements can exist in solid, liquid, or gaseous states. Gaseous elements, like noble gases and some nonmetals, are often colorless and unreactive. Recognizing the state of an element is crucial for determining its classification as a metal, nonmetal, or semimetal.

Reactivity of Elements

The reactivity of an element is influenced by its electron configuration and position in the periodic table. Nonmetals, especially noble gases, are generally less reactive than metals. Understanding the trends in reactivity helps in predicting the behavior of elements under various conditions.