Periodic Table: Key Groups & Elements

Grade 9 · Science · Flashcards

Master the main groups of the periodic table and their properties.

Flashcards

Alkali Metals (Group 1): Soft, highly reactive metals that explode in water. Examples: lithium, sodium, potassium.
Alkaline Earth Metals (Group 2): Reactive metals, less so than Group 1. Found in bones and shells. Examples: magnesium, calcium.
Halogens (Group 17): Highly reactive nonmetals that form salts with metals. Examples: fluorine, chlorine, bromine.
Noble Gases (Group 18): Extremely stable, nearly unreactive gases. Full outer electron shells. Examples: helium, neon, argon.
Transition Metals: Groups 3-12. Hard, dense metals with high melting points. Many are colorful in compounds. Examples: iron, copper, gold.
Metalloids: Elements with properties of both metals and nonmetals. Found along the staircase line. Examples: silicon, boron.
Atomic Number: The number of protons in an atom's nucleus. Determines what element it is.
Period: A horizontal row on the periodic table. Elements in the same period have the same number of electron shells.
Group / Family: A vertical column on the periodic table. Elements in the same group share similar chemical properties.
Valence Electrons: Electrons in the outermost shell. They determine how an element bonds with others.
Electronegativity: How strongly an atom attracts electrons in a bond. Increases left to right, bottom to top.
Ionization Energy: Energy needed to remove an electron. Increases left to right across a period.