Daily Science (on periodic table)Using different colors, color in (with a crayon or

colored pencil) the different families of the periodic table.

You should have the following families colored:Alkali MetalsAlkaline-Earth MetalsTransition metalsSemi-conductorsNon-metals in groups 14-16Metals in groups 13-16HalogensNoble gases

*Be sure to include a key on the back of your periodic table or on the last sheet in your notebook.

Pg. 57

Forming Compounds and Molecules

Chemical BondsThe forces that hold atoms or ions together

are chemical bonds.

Chemical StructureWe use 3 models to show chemical

structureBall-and-stick model:

Show the bond length and bond angleAtoms are balls and bonds are sticks

Space-filling model:Shows the space that the atoms take up

Structural formula:Chemical symbols are used to represent

atoms

Ball and Stick Model

Structural Formula

Space-filling model

BondingAtoms bond when their valence electrons

interact.Atoms bond so that they satisfy the octet

ruleThere are 4 different types of bonds:

IonicCovalentMetallicHydrogen

Ionic BondsFormed from the attraction between

oppositely charged ions.Formed between cation (positively charged)

and anion (negatively charged).Non-metal + metalFormed by the transfer of electronsSome atoms have more of an attraction for

electrons. This is called electronegativity.When melted or dissolved, they conduct

electricity.Ex. NaCl

Covalent BondsElectrons are sharedThey don’t usually conduct electronsNonmetal + nonmetalMore than one electron can be shared

creating double and triple bonds

Metallic BondsCalled “sea of electrons”Can conduct electricityAtoms are so closely packed that the outer

energy levels overlap.Usually occurs with transition metals

Hydrogen bondsOccur between hydrogen and either:

OxygenNitrogenFluorine

This is why some bugs can glide on top of water.

Polyatomic IonsSome compounds have ionic and covalent

bondsThey act as a single unitParenthesis group polyatomic ions togetherThe subscript on the outside of a

polyatomic ions applies to the whole ionEx: (NH4)2SO4