Unit 7 Ionic Bonding

Metals VS Nonmetals Metals Non-metals Located on the left side of the periodic table. Located on the right side of the periodic table.

Metals VS Non-Metals Chemical Properties Usually have 1-3 electrons in their outer shell. Lose their valence electrons easily and become positive ions. Have lower electronegativities. Usually have 4-8 electrons in their outer shell. Gain or share valence electrons easily and become negative ions. Have higher electronegativities.

Intro to Bonding Elements are the building materials of all the substances that make up all living and nonliving things. About 100 different elements Millions of different compounds (two or more elements combined) Only elements that exits alone are the Noble Gases – they are called monatomic elements All other elements need to combine to be “happy” (have 8 electrons in outer shell).

Molecules and Compounds A molecule is any combination of two or more atoms. Not all molecules are compounds. A compound is any combination of two or more different atoms. All compounds are molecules. H H O O O Diatomic molecules are elements that can’t exist alone in nature. They are Br2, I2, N2, Cl2, H2, O2, F2 Now write these on your ion chart

Atoms, Elements, Molecules, and Compounds 3 2 1

Valence Electrons Valence electrons— is the number of outermost electrons that an atom has available to lose, gain, or share. The valence electrons are the ones that take part in chemical changes, so the number of valence electrons determines an atom's chemical behavior.

Valence Electrons Elements in the same group have the same number of valence electrons. Transition metals vary. Note: Helium has 2 valence electrons.

Lewis Dot Diagrams Dot Diagrams are a depiction of an atom’s valence electrons. They are a powerful tool in helping you understand, see, and even predict molecular bonding.

Lewis Dot Diagrams

Oxidation Numbers The oxidation numbers tell you how many electrons an element will gain or lose. This tells you how it will combine with other elements. (Not the same as valence electrons) Atoms gain or lose electrons when near certain other elements to fulfill the octet rule: “If I 8 I full” Full electron levels are more stable. If an atom has 1 or 2 valence electrons it will lose them to have a full inner level. If an atom has 6 or 7 valence electrons, it will gain electrons to fill an electron level. It takes less energy to lose 1 electron than to lose 7.

Oxidation Numbers Write the oxidation numbers on your periodic table

Oxidation Numbers B 3+ N3- Br 1- K 1+ He 0 C 4+ H 1+

Ions and Neutral Atoms Ions (protons ≠ electrons) Atoms (protons = electrons) Ions are atoms or groups of atoms with a charge Ions have a different number of protons and electrons. If you have more electrons you will have a negative charge. (-) If you have a smaller amount of electrons you will have a positive charge. (+) Atoms are electrically neutral Neutral atoms have the same number of protons and electrons.

Ions and Neutral Atoms

Ions and Neutral Atoms

Ions There are two types of ions. A cation and an anion. Cations and anions are completely opposite of each other.

Cations vs Anions Cation Anion a positive ion (+) Losers of electrons All metals are cations The number of protons is now larger than the number of electrons Examples) K1+ has lost 1 eˉ Ca2+ has lost 2 eˉ a negative ion (-) Gainers of electrons All non-metals are anions Number of electrons has been increased and is now greater than the number of protons Examples) F1- gained 1 eˉ O2- gained 2 eˉ

Cations vs Anions

Cations VS Anions

Cations vs Anions 3 gained 1 gained 3 lost 6 lost 2 gained 6 gained

Polyatomic Ions A tightly bound group of atoms that behaves as a unit and has a positive or negative change. .