Ionic Charges The outer electrons on an atom are called: Valence electrons. Atoms want a Bohr-Rutherford Diagram that looks like a Noble Gas because… Noble Gases have the most stable structure. Usually, this means the atom ends up with a Charge.

Ions Ion= a Charged atom in which the number of ELECTRONS (-) is different from the number of PROTONS (+). Ionic Charge= is the number of positive (+) or negative (-) Charges on an atom. Ex: Mg+2

Groups Mg Be (Berylium)

So… Even though each element has a different # of PROTONS and ELECTRONS, each element in a group has a similar Bohr-Rutherford Diagram. This means they want to gain or lose the same number of Electrons. It also means elements in a Group will react similarly in Chemical Reactions.

Group Name and Number Noble gases Alkali Metals Halogens Alkali Earth Metals Transition metals

Cl & Na Chlorine Gas is poisonous. In terms of electrons, what does Chlorine want to do? -Gain an electron. So what would the Charge be? Sodium is highly reactive and toxic. In terms of electrons, what does Sodium want to do? Lose an electron. So what would the Charge be?

Cl & Na, cont’d What would happen if we put Na and Cl together? We get NaCl, a.k.a.: SALT!

Na + Cl Na+1 + electron + Cl Salt, what has Happened? Sodium (Na) gave up its Valence electron to the Chlorine (Cl). Na + Cl Na+1 + electron + Cl Na+1 + Cl-1 NaCl Why do you think they are now written together? Why are there no Charges?

Ionic Bonding Positives will be attracted to Negatives. The force of the attraction between a Positively Charged Ion and a Negatively Charged Ion is called an IONIC BOND. When two Ions Bond, they form an Ionic Compound. Ex. NaCl

Ionic Compounds Positive Ion is called a CATION. Negative Ion is called an ANION. Write down 2 other cations and anions that you think would fit together

Ionic Compounds Ca +2 + Cl Ca Cl -1 CaCl2 Notice the cross over of Charges The Cation is always written FIRST, Anion Second. Ionic compounds are made up of metals and non-metals, the metal is written FIRST. Ca +2 + Cl Ca Cl -1 CaCl2

Formation of Ionic Compounds Crossing Rule Ca+2 + Cl-1 CaCl2

Naming Ionic Compounds Regular names: Write the name of the metal first Replace the ending of the non-metal with –ide eg. Mg3P2 → Magnesium Phosphide

Naming Ionic Compounds Acids: Recognized by the H+ ion out front (but not like in water, H2O, that’s covalent) Name it using the word “hydro”, then the non-metal, but with the ending -ic eg. HCl → Hydrochloric acid Eg. HF → Hydrofluoric acid Try HI → Hydroiodic acid

Practice Na+1 + F-1  NaF Sodium fluoride H+1 + Br-1  HBr Hydrobromic acid Ca+2 + Cl-1  CaCl2 Calcium chloride