Atoms, Bonding, and the Periodic Table Chapter 5 sec 1 Mr. Sapalicio Monterey Highlands Physical Science

Valence Electrons and Bonding Valence electrons- Valence electrons are the electrons that are in the shell or energy level that is farthest from the nucleus The number of valence electrons in an atom of an element determines many properties of an element, including the ways it bonds with other atoms. WHAT?

Chemical Bonds and Stability Atoms are more stable and less likely to react when they have 8 valence electrons Atoms react in a way that makes each atom more stable When bonds form, one of 2 things happens The number of valence electrons increases to 8 or The atom gives up its loosely held extra electrons

Electron Dot Diagrams H He Li Be

Valence Electrons and Bonding (cont.) Chemical Bond- The force that holds atoms together. O------O When atoms bond electrons can be shared or transferred between atoms. This change results in a chemical reaction.  A chemical bond is the attraction caused by the electromagnetic force between opposing charges

How the Periodic Table works Periods- start with 1 valence electron and end with 8 Groups 1, 2, 13-18 give the number of valence electrons. Groups 3-12 vary between 1, 2, or 3 valence electrons. Inert gases- group 18, very unreactive, they don’t transfer electrons.

How the Periodic Table works Semimetals- lie along the zigzag line between metals and nonmetals. They have 3-6 valence electrons Hydrogen-