Question

Identify cach of the following elements as a metal, nonmetal, or metalloid: (a) phosphorus, (b) strontium, (c) manganese, (d) sclenium, (c) sodium, (f) krypton.

Short answer

(a) Phosphorus: Nonmetal, (b) Strontium: Metal, (c) Manganese: Metal, (d) Selenium: Nonmetal, (e) Sodium: Metal, (f) Krypton: Nonmetal

Step-by-step solution

Locate the element on the periodic table

Look at the periodic table and locate each element using their chemical symbol. Take a note of their groups and periods.

Identify the properties

Based on the element's position on the periodic table, identify their general properties and characteristics, including typical properties of metals, nonmetals, and metalloids.

Classify each element

Now that you know the properties of each element, classify them as either a metal, nonmetal, or metalloid based on their characteristics. Here is the classification for each given element: (a) Phosphorus (P): - Located in Group 15, Period 3 - Properties: Non-metal - Classification: Nonmetal (b) Strontium (Sr): - Located in Group 2, Period 5 - Properties: Alkaline earth metal - Classification: Metal (c) Manganese (Mn): - Located in Group 7, Period 4 - Properties: Transition metal - Classification: Metal (d) Selenium (Se): - Located in Group 16, Period 4 - Properties: Non-metal - Classification: Nonmetal (e) Sodium (Na): - Located in Group 1, Period 3 - Properties: Alkali metal - Classification: Metal (f) Krypton (Kr): - Located in Group 18, Period 4 - Properties: Noble gas - Classification: Nonmetal

Key concepts

Periodic Table

The Periodic Table is a comprehensive chart that organizes all known elements according to their atomic number, electron configurations, and recurring chemical properties. Elements are arranged in rows called periods and columns known as groups or families. As you move from left to right across a period, the atomic number increases, and elements transition from metals to metalloids to nonmetals.

Understanding the layout of the Periodic Table is crucial for identifying an element's properties. For instance, metals are typically found on the left side and center, while nonmetals reside on the right. Metalloids, which exhibit both metallic and nonmetallic properties, form a zigzag line separating metals and nonmetals. Alkali metals are in Group 1, alkaline earth metals in Group 2, transition metals are in the middle, nonmetals in Groups 16 and 17, and noble gases in Group 18. Recognizing these patterns allows for quick classification of elements as metal, nonmetal, or metalloid.

Metals, Nonmetals, and Metalloids

Metals, nonmetals, and metalloids represent categories of elements with distinct chemical and physical properties. Metals are characterized by their shiny appearance, malleability, ductility, and excellent conductivity for heat and electricity. They tend to lose electrons during chemical reactions, forming positive ions or cations.

Nonmetals, on the other hand, generally have a dull appearance and are poor conductors of heat and electricity. They tend to gain or share electrons when undergoing chemical reactions, often forming negative ions or anions. Oxygen, nitrogen, and carbon are common examples of nonmetals that play essential roles in biological and chemical processes.

Metalloids behave like a hybrid of metals and nonmetals. They can conduct electricity better than nonmetals but not as well as metals, a property that makes them useful in semiconductors. Boron, silicon, and arsenic are typical metalloids with properties that make them versatile in various technological applications.

Chemical Properties

The chemical properties of an element are defined by its ability to undergo chemical changes or reactions. These properties are determined by an element's electron configuration and its position on the Periodic Table, directly influencing how it interacts with other elements. For example, metals often react by losing electrons to form cations, whereas nonmetals tend to gain electrons to form anions.

Other chemical properties include reactivity, which is how readily an element will form a chemical bond with others, and affinity for electron acquisition, which can be measured through electronegativity. The noble gases, such as krypton, are notable for their low reactivity due to their complete valence electron shell, making them mostly inert and less likely to participate in chemical reactions.

Understanding the chemical properties of elements is critical for predicting the outcomes of chemical reactions, determining the type of bond that will form between atoms, and explaining the reactive tendencies of different substances. Accurate knowledge of these properties is essential for students and professionals in the field of chemistry and related sciences.