Chemical Bonding, Mass, and Element Types

Chemical Bonding and Structure

Forming Molecules

In composites, clustering involves forming molecules. Atoms of different non-metal elements are joined to form molecules.

Ionic Crystals

When metals bind to nonmetals, they form ions of two types. Metals typically form positive ions, and nonmetals form negative ions, which are held together by electrostatic attraction.

For example, a sodium atom gives one electron to a chlorine atom, becoming Na⁺ and Cl^- ions. These ions attract each other. When this happens, many atoms can form a crystal lattice where the ions alternate in a three-dimensional network.

Atomic and Molecular Mass

The atomic mass of an atom is the average mass of its isotopes. It is typically found in the periodic table, often below the element symbol. The symbol Ar represents atomic mass.

The molecular mass of a molecule is calculated by adding the atomic masses of all the atoms forming it.

Molar Mass and the Mole Concept

The mole is a unit representing a specific quantity of substance. One mole of any substance contains Avogadro's number (N_A) of particles, which is approximately 6.022 × 10²³.

A mole can represent atoms, molecules, or ions. For example, 1 mole of water molecules is a quantity of water that contains 6.022 × 10²³ water molecules.

The molar mass (mass of one mole) of a substance in grams is numerically equal to its atomic or molecular mass in atomic mass units (amu).

For example, the molecular mass of H₂O is 18 amu. Therefore, the molar mass of H₂O is 18 grams per mole (g/mol).

Classification of Elements

Metals

• Lithium, Beryllium, Sodium, Magnesium, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Aluminum, Rubidium, Strontium, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Rhodium, Silver, etc.

Non-metals

• Hydrogen, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Helium, Phosphorus, Sulfur, Chlorine, Argon, Selenium, Bromine, Krypton, Iodine, Xenon, Astatine, Radon.

Semi-metals

• Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium.

List of Elements and Symbols

• H (Hydrogen)
• Li (Lithium)
• Na (Sodium)
• K (Potassium)
• Rb (Rubidium)
• Cs (Cesium)
• Fr (Francium)
• Be (Beryllium)
• Mg (Magnesium)
• Ca (Calcium)
• Sr (Strontium)
• Ba (Barium)
• Ra (Radium)
• Sc (Scandium)
• Y (Yttrium)
• La (Lanthanum)
• Ac (Actinium)
• Ti (Titanium)
• V (Vanadium)
• Cr (Chromium)
• Mn (Manganese)
• Fe (Iron)
• Co (Cobalt)
• Ni (Nickel)
• Pd (Palladium)
• Pt (Platinum)
• Cu (Copper)
• Ag (Silver)
• Au (Gold)
• Zn (Zinc)
• Cd (Cadmium)
• Hg (Mercury)
• B (Boron)
• Al (Aluminum)
• Ga (Gallium)
• In (Indium)
• Tl (Thallium)
• C (Carbon)
• Si (Silicon)
• Ge (Germanium)
• Sn (Tin)
• Pb (Lead)
• N (Nitrogen)
• P (Phosphorus)
• As (Arsenic)
• Sb (Antimony)
• Bi (Bismuth)
• O (Oxygen)
• S (Sulfur)
• Se (Selenium)
• Te (Tellurium)
• Po (Polonium)
• F (Fluorine)
• Cl (Chlorine)
• Br (Bromine)
• I (Iodine)
• At (Astatine)
• He (Helium)
• Ne (Neon)
• Ar (Argon)
• Kr (Krypton)
• Xe (Xenon)
• Rn (Radon)