Use the periodic table to find the missing information

Chlorine (Cl)

1.Number of protons 2.Number of electrons 3.Number of neutrons 4.Number of energy shells5.Number of valence electron(s)

17

17

18

3

7

ReviewReview IsotopesIsotopes

CompoundsCompounds

Matter made up of two Matter made up of two or more elements or more elements chemically combinedchemically combined

The elements lose their The elements lose their individual propertiesindividual properties

CompoundsCompounds The new compounds The new compounds

formed have new formed have new propertiesproperties

Ratio of their parts are Ratio of their parts are exactexact

NaCl, HNaCl, H22O, COO, CO22

CompoundsCompounds Molecule-smallest Molecule-smallest unit of a compoundunit of a compound

Ionic BondIonic Bond Strong attractive Strong attractive force between ions of force between ions of opposite charges opposite charges

Ionic BondIonic Bond Valence electrons can be Valence electrons can be

transferredtransferred From one atom to anotherFrom one atom to another If an atom gains or loses If an atom gains or loses

electrons, it becomes electrons, it becomes electrically chargedelectrically charged

IonIon

Ionic BondIonic Bond Ionic compounds are Ionic compounds are usually formed from a usually formed from a metal and a nonmetal metal and a nonmetal

Ionic Bond• NaCl

• MgO

Properties of Ionic CompoundsProperties of Ionic Compounds

Form strong 3-D crystal Form strong 3-D crystal structuresstructures

Hard, rough, and brittleHard, rough, and brittleSolid at room tempSolid at room tempHigh melting pointsHigh melting points

Properties of Ionic CompoundsProperties of Ionic Compounds

Tend to dissolve in Tend to dissolve in waterwater

This solution conducts This solution conducts electricity very wellelectricity very well