How Elements Form Compounds

This is how elements combine to form compounds. In order for atoms to have a stable valence shell, they will link up with other atoms by stealing, giving up or sharing electrons. This is how elements combine to form compounds. Top: limestone. Bottom left: calcium chloride (road salt) Bottom right: copper II sulfate: ALL EXAMPLES OF IONIC COMPOUNDS

There are two major types of compounds that can form between atoms: 1. Ionic compounds: where metals (+) bonds with non-metals (-) *stealing 2. Molecular (Covalent) compounds: where non-metals bond with other non-metals *sharing

Ionic Compounds Ex: Sodium + Chlorine Sodium will “share” it’s one extra electron with chlorine (who is missing one)

Here we see that Na (metal) will give it’s valence electron to Cl (non-metal) so that they both have stable shells! Once this happens, the ionic charge of Na will be 1+ and the ionic charge of Cl will be 1-. These two opposing charges will attract each other and a chemical bond will be formed creating the compound sodium chloride (NaCl)

Sometimes, more than one electron can be transferred! Ex: Calcium + oxygen Calcium has two extra electrons that it will share with oxygen. Ca+2 O-2 This compound’s name is

Sometimes, more than one atom of each element will have to be involved. Ex: calcium + chlorine This compound’s name is

Naming Compounds Ionic Compounds Write the name of the first element as it appears on the periodic table Change the ending of the second element to “-ide” Example: NaCl Sodium Chloride

Naming Ionic Compounds Name the following Ionic Compounds: LiF Be3N2 MgCl2 CaO AlF3 K2S ZnBr2 CaBr2

Build Be3N2 They always equal zero! What do you notice about the overall charge of the ionic compound if you add the metal’s charges with the non-metal’s charge?

Naming when you have metals with more than one Charge Some metals make more than one ionic charge. Most of these are found in the transition metals on the PT If you use a metal that can make more than one ionic charge, you must use a roman numeral following the metal’s name in indicate which ion charge was used. The name of the non-metal still ends in “-ide”. NOTE: The little number in the formulas is NOT it’s charge! It represents HOW MANY of the ions are used in the formula.

Build the following molecules with your ion fit kit and then give them a name in your notes. CuBr FeO CuBr2 Fe2O3 NiI3 Sn3N2 NiI2 Sn3N4

What pattern appears between the charges of the ions and how many of each ion there are in the formula? The charge of the metal is how many non-metals you need in the formula and vice versa. **Most of the time!

Naming with Polyatomic Ions: A polyatomic ion is a group of atoms that together hold an overall ionic charge If a polyatomic ion is in a formula, just state its name as written. You do NOT change it’s ending.

Build the following molecules with your ion fit kit and then give them a name in your notes. Na2SO4 NH4Cl Al(OH)3 Fe(NO3)3 Zn(BrO3)2 (NH4)3PO4