Question

a. Classify the following elements as metals or nonmetals: $$\begin{array}{lll}\mathrm{Mg} & \mathrm{Si} & \mathrm{Rn} \\ \mathrm{Ti} & \mathrm{Ge} & \mathrm{Eu} \\ \mathrm{Au} & \mathrm{B} & \mathrm{Am} \\\ \mathrm{Bi} & \mathrm{At} & \mathrm{Br}\end{array}$$ b. The distinction between metals and nonmetals is really not a clear one. Some elements, called metalloids, are intermediate in their properties. Which of these elements would you reclassify as metalloids? What other elements in the periodic table would you expect to be metalloids?

Short answer

In summary, the given elements can be classified as follows: Metals: \( \mathrm{Mg}\), \( \mathrm{Ti}\), \( \mathrm{Eu}\), \( \mathrm{Au}\), \( \mathrm{Am}\), and \( \mathrm{Bi}\). Nonmetals: \( \mathrm{Rn}\), \( \mathrm{B}\), \( \mathrm{At}\), and \( \mathrm{Br}\). Metalloids: \( \mathrm{Si}\) and \( \mathrm{Ge}\). Other possible metalloids include: \( \mathrm{B}\), \( \mathrm{As}\), \( \mathrm{Sb}\), \( \mathrm{Te}\), and \( \mathrm{Po}\).

Step-by-step solution

Identify Metals and Nonmetals

To classify the elements as metals and nonmetals, we will reference the periodic table. Metals are typically located on the left side and in the center of the periodic table, while nonmetals are located on the right side. Using this information, we can classify the given elements as follows: Metals: \( \mathrm{Mg} \) - Magnesium \( \mathrm{Ti} \) - Titanium \( \mathrm{Eu} \) - Europium \( \mathrm{Au} \) - Gold \( \mathrm{Am} \) - Americium \( \mathrm{Bi} \) - Bismuth Nonmetals: \( \mathrm{Rn} \) - Radon \( \mathrm{B} \) - Boron \( \mathrm{At} \) - Astatine \( \mathrm{Br} \) - Bromine

Identify Metalloids

Metalloids are elements with properties that fall between those of metals and nonmetals. The most commonly recognized metalloids are Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, and Polonium. From the given list, we can classify the following elements as metalloids: \( \mathrm{Si} \) - Silicon \( \mathrm{Ge} \) - Germanium

Identify other possible metalloids

As mentioned earlier, the commonly recognized metalloids are: \( \mathrm{B} \) - Boron \( \mathrm{Si} \) - Silicon \( \mathrm{Ge} \) - Germanium \( \mathrm{As} \) - Arsenic \( \mathrm{Sb} \) - Antimony \( \mathrm{Te} \) - Tellurium \( \mathrm{Po} \) - Polonium In conclusion, using the periodic table, we were able to classify the given elements as metals, nonmetals, and metalloids.

Key concepts

Metals

Metals are elements that are typically shiny, malleable, and good conductors of heat and electricity. They are generally found on the left side and towards the center of the periodic table. Here are some key characteristics of metals:

• Luster: Metals have a shiny appearance when polished.
• Malleability and Ductility: Metals can be hammered into thin sheets or stretched into wire without breaking.
• Conductivity: They are excellent conductors of electricity and heat.
• High Density: Metals usually have high density and melting points.
• Solid State: Most metals are solid at room temperature, with mercury being a notable liquid exception.

These properties make metals indispensable in industrial applications. For example, magnesium (\(\mathrm{Mg}\)), titanium (\(\mathrm{Ti}\)), europium (\(\mathrm{Eu}\)), gold (\(\mathrm{Au}\)), americium (\(\mathrm{Am}\)), and bismuth (\(\mathrm{Bi}\)) are just a few metals with widespread uses across various industries.

Nonmetals

Nonmetals differ significantly from metals, exhibiting diverse chemical and physical properties. Located on the right side of the periodic table, they serve crucial roles in biological and chemical processes. Key traits of nonmetals include:

• Varied Appearance: Nonmetals can have a dull surface and come in different colors.
• Brittle Nature: They tend to break or shatter rather than bend when subjected to stress.
• Poor Conductors: Nonmetals are generally poor conductors of heat and electricity, making them good insulators.
• Low Density: Nonmetals often have lower densities compared to metals.
• Gaseous or Solid: At room temperature, nonmetals exist in gaseous or solid forms, with bromine (\(\mathrm{Br}\)) being a liquid exception.

Examples from the exercise include radon (\(\mathrm{Rn}\)), boron (\(\mathrm{B}\)), astatine (\(\mathrm{At}\)), and bromine (\(\mathrm{Br}\)), which play essential roles in various chemical reactions and biological functions.

Metalloids

Metalloids straddle the line between metals and nonmetals, possessing properties characteristic of both categories. These elements often behave interchangeably depending on the conditions they are subjected to. Characteristics of metalloids include:

• Semi-Conductivity: They are moderate electrical conductors, which makes them valuable in the electronics industry.
• Physical Appearance: Metalloids can display a metallic luster but are generally more brittle than metals.
• Chemical Behavior: Metalloids can exhibit varying oxidative and reductive behavior in chemical reactions.

Commonly recognized metalloids include silicon (\(\mathrm{Si}\)) and germanium (\(\mathrm{Ge}\)), both vital for semiconductors and electronic devices. The classification of boron (\(\mathrm{B}\)) as a metalloid also arises from its intermediate properties.

Element Classification

Classifying elements in the periodic table involves identifying metals, nonmetals, and metalloids based on their properties. Understanding this classification assists in predicting the behavior and reactions of elements, which is essential in both academic and applied chemistry.

• Periodic Trends: The periodic table is structured to reflect the similarities between elements. For example, metals typically populate the left and central sections, nonmetals the upper right, and metalloids act as a bridge between these two categories.
• Applications: Knowing the classification helps in determining an element's potential uses. Metals are often used in construction and electronics, nonmetals in organic compounds and insulators, and metalloids in semiconductors.
• Predictive Tool: The arrangement of elements enables scientists and students to predict an element's properties and chemical behavior based on its position and neighbors in the table.

Through recognizing these categories and the elements associated with each, such as those provided in the exercise, one gains a comprehensive overview of the chemical elements and their applications.