1. The Periodic Table of Elements
History & Structure
● Designer: Dmitri Mendeleev (1869).
● Periods (Rows): Elements have the same number of atomic orbitals.
● Groups (Columns): Elements have similar chemical properties and the same number of
electrons in their outermost shell.
Element Categories
Category Properties Examples
Metals Good conductors of heat & Iron (Fe), Gold (Au), Copper
electricity, ductile, shiny, (Cu)
malleable.
Non-Metals Poor conductors, brittle when Oxygen (O), Carbon (C), Sulfur
solid, dull (not shiny). (S)
Metalloids Characteristics of both; semi- Silicon (Si), Arsenic (As), Boron
conductors (conduct under (B)
specific conditions).
Electronic Blocks
● s-Block: Hydrogen (H), Lithium (Li), Magnesium (Mg)
● p-Block: Carbon (C), Nitrogen (N), Fluorine (F), Neon (Ne)
● d-Block: Iron (Fe), Copper (Cu), Nickel (Ni)
● f-Block: Uranium (U), Thorium (Th), Lanthanum (La)
2. Radioactivity & Nuclear Physics
Fundamentals of Radiation
● Electromagnetic Radiation: Energy traveling in waves through electric and magnetic
fields.
● Nuclear Radiation: Energy emitted from the nucleus of an atom.
● Radioisotopes: Elements with an unstable, radioactive nucleus.
● Ionization: The process of an atom losing or gaining electrons to become an Ion.
○ Risks: Exposure to high levels causes damage to living things (DNA damage).
○ Side Effects: Nausea, vomiting, skin redness, hair loss.
○ Long-term Risks: Increased risk of cancer later in life.
Types of Radiation
Type Symbol Penetrating Ionizing Power Stopped By Range
Power
Alpha α Least Most ionizing Paper / Skin Short
penetrating
Beta β Medium Medium Aluminium / Medium
History & Structure
● Designer: Dmitri Mendeleev (1869).
● Periods (Rows): Elements have the same number of atomic orbitals.
● Groups (Columns): Elements have similar chemical properties and the same number of
electrons in their outermost shell.
Element Categories
Category Properties Examples
Metals Good conductors of heat & Iron (Fe), Gold (Au), Copper
electricity, ductile, shiny, (Cu)
malleable.
Non-Metals Poor conductors, brittle when Oxygen (O), Carbon (C), Sulfur
solid, dull (not shiny). (S)
Metalloids Characteristics of both; semi- Silicon (Si), Arsenic (As), Boron
conductors (conduct under (B)
specific conditions).
Electronic Blocks
● s-Block: Hydrogen (H), Lithium (Li), Magnesium (Mg)
● p-Block: Carbon (C), Nitrogen (N), Fluorine (F), Neon (Ne)
● d-Block: Iron (Fe), Copper (Cu), Nickel (Ni)
● f-Block: Uranium (U), Thorium (Th), Lanthanum (La)
2. Radioactivity & Nuclear Physics
Fundamentals of Radiation
● Electromagnetic Radiation: Energy traveling in waves through electric and magnetic
fields.
● Nuclear Radiation: Energy emitted from the nucleus of an atom.
● Radioisotopes: Elements with an unstable, radioactive nucleus.
● Ionization: The process of an atom losing or gaining electrons to become an Ion.
○ Risks: Exposure to high levels causes damage to living things (DNA damage).
○ Side Effects: Nausea, vomiting, skin redness, hair loss.
○ Long-term Risks: Increased risk of cancer later in life.
Types of Radiation
Type Symbol Penetrating Ionizing Power Stopped By Range
Power
Alpha α Least Most ionizing Paper / Skin Short
penetrating
Beta β Medium Medium Aluminium / Medium
