Question

Locate each of the following elements in the periodic table; give its name and atomic number, and indicate whether it is a metal, metalloid, or nonmetal: (a) Li, (b) Sc, (c) Ge, (d) Yb, (e) \(\mathrm{Mn}\), (f) Sb, (g) Xe.

Short answer

(a) Lithium (Li): Atomic number 3, Metal; (b) Scandium (Sc): Atomic number 21, Metal; (c) Germanium (Ge): Atomic number 32, Metalloid; (d) Ytterbium (Yb): Atomic number 70, Metal; (e) Manganese (Mn): Atomic number 25, Metal; (f) Antimony (Sb): Atomic number 51, Metalloid; (g) Xenon (Xe): Atomic number 54, Nonmetal.

Step-by-step solution

(a) Li

Element: Lithium (Li) Atomic number: 3 Category: Metal

(b) Sc

Element: Scandium (Sc) Atomic number: 21 Category: Metal

(c) Ge

Element: Germanium (Ge) Atomic number: 32 Category: Metalloid

(d) Yb

Element: Ytterbium (Yb) Atomic number: 70 Category: Metal

(e) Mn

Element: Manganese (Mn) Atomic number: 25 Category: Metal

(f) Sb

Element: Antimony (Sb) Atomic number: 51 Category: Metalloid

(g) Xe

Element: Xenon (Xe) Atomic number: 54 Category: Nonmetal

Key concepts

Atomic Number

The atomic number is a fundamental concept in chemistry, representing the number of protons in the nucleus of an atom. This number not only defines the identity of an element but also its position in the periodic table. For example, Lithium (Li) has an atomic number of 3, which indicates it has three protons in its nucleus. This is why Li is placed third on the periodic table.
Each element has a unique atomic number, which distinguishes it from other elements. Since atoms are electrically neutral overall, the atomic number also reveals the number of electrons in a neutral atom, playing a vital role in chemical reactions. Understanding the atomic number is essential as it helps predict how an element will behave chemically.

Elements

Elements are pure substances consisting entirely of one type of atom. Present on the periodic table, each element is unique and represented by a chemical symbol, often derived from its name. For example, Scandium is represented by the symbol "Sc."
Elements are the building blocks of matter and, through their interactions, form the vast array of substances we encounter daily. The periodic table organizes elements based on increasing atomic number and similar chemical properties, making it easier to study and predict their behaviors.
Importantly, there are over 118 elements currently recognized, ranging from simple gases like Hydrogen to complex, synthetic elements like Oganesson.

Metals

Metals are a broad category on the periodic table known for their distinct physical and chemical properties. They are typically good conductors of electricity and heat, malleable, ductile, and often have a shiny luster. Elements like Lithium (Li), Scandium (Sc), Ytterbium (Yb), and Manganese (Mn) are all classified as metals.
Most metals are solid at room temperature, with the notable exception being Mercury. The metallic bonding present in metals allows atoms to slide past each other when force is applied, which accounts for properties like malleability. This category plays a crucial role in both industry and technology, providing resources for building and manufacturing.

Metalloids

Metalloids are elements that have properties in between metals and nonmetals. They display a mixture of metallic and non-metallic characteristics and often behave as semiconductors. Germanium (Ge) and Antimony (Sb) are two examples of metalloids found in the periodic table.
These elements can conduct electricity and heat better than nonmetals but not as well as metals, which makes them valuable in the electronics industry, particularly in semiconductors for gadgets and computers. Their positioning on the periodic table is typically at the dividing line between metals and nonmetals, often forming a "staircase" pattern.

Nonmetals

Nonmetals are elements characterized by a wide range of properties. Generally, they are poor conductors of heat and electricity and have a greater tendency to gain electrons in chemical reactions. Xenon (Xe) is an example of a nonmetal, often showing noble gas characteristics with very low reactivity.
Nonmetals are found predominantly on the right side of the periodic table. They can exist in different states of matter: gases (like oxygen), solids (like sulfur), or liquids (like bromine). These elements play crucial roles in bio-organic processes and the atmosphere, making them essential for life and a variety of chemical industries.