How atoms form compounds

What is a compound? Compounds are pure substances that contain two or more elements. Elements are pure substances made from one type of atom COMPOUNDS HAVE DIFFERENT PROPERTIES THAN THE ELEMENTS THAT MAKE THEM UP Chemical formulas are a short hand way of describing what is in a compound

IONS Ions are an atom that is no longer neutral because it has gained or lost electrons Positive ions lose electrons Has more protons than electrons Represented by the element’s symbol with a superscript plus sign (+) Negative ions Has more electrons than protons Represented by the element’s symbol with a superscript negative sign (-)

Ionic Bonds Ionic bonds require the transferring of electrons in order to form a chemical bond to make a compound Two or more elements that are forced together is a bond

Ionic Compounds Using the periodic table, you can figure out positive and negative ions Using the number of valence electrons and Lewis Dot diagrams , you can figure out if they will combine EXAMPLE: Group 1 with Group 17 form salts

Foldable Follow directions on pg 215 Info for Ionic bond: pg220-222 Info for Metallic bond: pg231-232 HW: fill in metallic bond information Tomorrow we will fill in the covalent bond information