This definitions covers Key Definitions within The Periodic Table for GCSE Chemistry. Revise The Periodic Table in Atomic Structure for GCSE Chemistry with 22 exam-style questions and 24 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 8 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Group: A vertical column in the periodic table. Elements in the same group have the same number of outer shell electrons and similar chemical properties.
Period: A horizontal row in the periodic table. Elements in the same period have the same number of occupied electron shells.
Metal: An element that is typically shiny, malleable, conducts electricity and heat, and forms positive ions. Found on the left and centre of the periodic table.
Non-metal: An element with properties opposite to metals — poor conductors, brittle in solid form, often gases. Found on the right of the periodic table.
Atomic number: The number of protons in the nucleus; the property used to order elements in the modern periodic table.
Practice questions for The Periodic Table
How are elements arranged in the modern periodic table?
Mendeleev's periodic table was eventually accepted by other scientists. Explain why scientists were convinced that his table was correct.