Element Classes Flashcards

Element Classes Overview

• Alkali Metals are found in Group 1 (1A) of the periodic table; they are highly reactive and have one valence electron.
• Alkaline Earth Metals occupy Group 2 (2A); they are less reactive than alkali metals and possess two valence electrons.
• Transition Metals make up Groups 3-12 (_B); they are characterized by a wide range of oxidation states and are known for forming colorful compounds.

Halogens and Noble Gases

• Halogens are located in Group 17 (7A); they are very reactive nonmetals with seven valence electrons and include elements like fluorine and chlorine.
• Noble Gases, found in Group 18 (8A), are inert due to their complete valence shell. They include helium, neon, and argon.

Metal Classification

• Metals are situated to the left of the zig-zag line on the periodic table; they are typically solid at room temperature, good conductors of heat and electricity.
• Metalloids, also known as semi-metals, are positioned on the zig-zag line (except for aluminum and astatine); they have properties intermediate between metals and nonmetals.

Nonmetals

• Nonmetals are found to the right of the zig-zag line; they are varied in state (some gases, some solids) and generally poor conductors.

Atomic Structure

• Energy Levels refer to the shells that electrons occupy around the nucleus; all elements in the same horizontal period have the same number of energy levels, which increase by one as you move vertically down a group.
• Valence Electrons are the outermost electrons that participate in chemical bonding; their number is indicated in Lewis diagrams and increases by one as you move from left to right across a period, remaining consistent within a group.