IGCSE Chemistry: Periodic Table and Electron Configuration

Periodic Table and Groups

• Group 1: Alkali metals
• Group 2: Alkaline earth metals
• Group 17: Halogens
• Group 18: Noble gases

Electronic Configuration

• The 2, 8, 8 model represents the arrangement of electrons in atoms of the first 20 elements
• The number of energy levels (orbitals) and valence electrons can be determined based on an element's position in the periodic table
• Valence electrons are responsible for chemical bonding

Noble Gases

• Noble gases have a full outer energy level, making them unreactive
• The electronic configuration of noble gases is stable and does not easily react with other elements

Ionic Compounds

• Formed by the transfer of electrons between atoms, resulting in cations and anions
• Cations are formed by losing electrons, while anions are formed by gaining electrons
• Electrostatic attraction between oppositely charged ions holds the compound together
• Example: Sodium (Na) loses an electron to form Na+ (cation), while Chlorine (Cl) gains an electron to form Cl- (anion)

Covalent Compounds

• Formed by sharing electrons between atoms
• Covalent bonds involve the sharing of one or more pairs of electrons
• Example: Hydrogen (H) shares its electron with Chlorine (Cl) to form Hydrogen Chloride (HCl)

Bonding Diagrams

• Dot and cross diagrams can be used to represent ionic and covalent bonding
• Dots represent electrons, while crosses represent nuclei

Compound Nomenclature

• Covalent compounds have a prefix system to indicate the number of atoms of each element
• Ionic compounds have a suffix system to indicate the charge on the ion

Ionic Compound Formation

• Can be predicted based on the ions formed by elements
• Elements in Groups 1, 2, and 13-17 form ions based on their valence electrons
• The formula of an ionic compound can be predicted based on the ions reacting together

Chemical Equations

• Can be written in word form and balanced
• Chemical equations represent the reactants, products, and direction of a chemical reaction

Test your knowledge of the periodic table and electron configuration in IGCSE Chemistry. Topics include group names, electronic arrangements of the first 20 elements, energy levels, and valence electrons.