Unit 2: Chemical Interactions Chapter 5: Atoms & Bonding Big Idea: Atoms of different elements combine to form compounds by gaining, losing, or sharing electrons

4 Sections Atoms, Bonding, & the Periodic Table Ionic Bonds Covalent Bonds Bonding in Metals Mrs. Lee - Ch 5

Sec 1: Atoms, Bonding, & the Periodic Table KEY CONCEPTS The number of valence electrons in an atom of an element determines many properties of that element, including the ways in which the atom can bond with other atoms The periodic table reveals the underlying atomic structure of atoms, including the arrangement of the electrons Mrs. Lee - Ch 5

Sec 1: Key Terms Valence electron Electron dot diagram Chemical bond Mrs. Lee - Ch 5

Sec 2: Scientific Inquiry KEY CONCEPTS Ionic bonds form as a result of the attraction between positive & negative ions When ionic compounds form, the charges on the ions balance out Mrs. Lee - Ch 5

Sec 2: Ionic Bonds (cont’d) For an ionic compound, the name of the positive ion comes first, followed by the name of the negative ion In general, ionic compounds are hard, brittle crystals that have high melting points & conduct electricity when dissolved in water Mrs. Lee - Ch 5

Sec 2: Key Terms Ion Polyatomic ion Ionic bond Ionic compound Chemical formula Subscript Crystal Mrs. Lee - Ch 5

Sec 3: Covalent Bonds KEY CONCEPTS The force that holds atoms together in a covalent bond is the attraction of each atom’s nucleus for the shared pair of electrons Molecular compounds have low melting & boiling points & do not conduct electric current Unequal sharing of electrons causes bonded atoms to have slight electrical charges Mrs. Lee - Ch 5

Sec 3: Key Terms Covalent bond Molecule Double bond Triple bond Molecular compound Polar bond Nonpolar bond Mrs. Lee - Ch 5

Sec 4: Bonding in Metals KEY CONCEPTS Alloys are generally stronger & less reactive than the pure metals from which they are made Metal atoms combine in regular patterns in which the valence electrons are free to move from atom to atom Mrs. Lee - Ch 5

Sec 4: Bonding in Metals (cont’d) The “sea of electrons” model of metallic bonding helps explain the malleability, ductility, luster, high electrical conductivity, & high thermal conductivity of metals Mrs. Lee - Ch 5

Sec 4: Key Terms Alloy Metallic bond Mrs. Lee - Ch 5