Objectives Be able to explain why atoms sometimes join to form bonds Be able to explain why atoms sometimes join to form bonds Be able to explain why some atoms transfer their valence electrons to form ionic bonds and others share valence electrons to form covalent bonds Be able to explain why some atoms transfer their valence electrons to form ionic bonds and others share valence electrons to form covalent bonds Be able to differentiate between ionic, covalent, and metallic bonds Be able to differentiate between ionic, covalent, and metallic bonds Compare the properties of substances with different types of bonds Compare the properties of substances with different types of bonds

Important Vocabulary Stable electron configuration Stable electron configuration Ionic bond Ionic bond Metallic bond Metallic bond Covalent bond Covalent bond Polar covalent bond Polar covalent bond Dipole Dipole Non-polar covalent bond Non-polar covalent bond Polyatomic ions Polyatomic ions

What Holds Bonded Atoms Together? 1.A stable electron configuration 2.Bonds can bend without breaking 3.Bonds can stretch without breaking

Stable Electron Configuration Happens when atoms have full outermost s & p orbitals Happens when atoms have full outermost s & p orbitals Bonded atoms also have electron configuration structures similar to noble gases Bonded atoms also have electron configuration structures similar to noble gases

Bonds can Bend & Stretch Bonds are not completely rigid Bonds are not completely rigid Many act like flexible springs in which the distance of the nuclei of the atoms changes Many act like flexible springs in which the distance of the nuclei of the atoms changes

Types of Bonds Ionic Ionic Metallic Metallic Covalent Covalent  Polar  Non polar  Polyatomic Ions

Ionic Bonds Are formed between oppositely charged ions Are formed between oppositely charged ions They are formed by the transfer of electrons, one atom loses electrons and the other gains electrons They are formed by the transfer of electrons, one atom loses electrons and the other gains electrons  i.e. Na + + Cl - = NaCl Ionic compounds are in the form of ion networks NOT molecules Ionic compounds are in the form of ion networks NOT molecules Ionic compounds when melted or dissolved in water can conduct electricity Ionic compounds when melted or dissolved in water can conduct electricity

Ionic Bonds

Metallic Bonds Is a bond formed by the attraction between positively charged metal ions & the electrons around them Is a bond formed by the attraction between positively charged metal ions & the electrons around them Electrons move freely between metal atoms Electrons move freely between metal atoms Attractive forces between nuclei and neighboring atom’s electrons pack the atoms close together, overlapping the energy levels Attractive forces between nuclei and neighboring atom’s electrons pack the atoms close together, overlapping the energy levels

Metallic Bonds

Covalent Bonds Compounds made of molecules have covalent bonds Compounds made of molecules have covalent bonds Often formed between nonmetals Often formed between nonmetals Can be solids, liquids, or gases Can be solids, liquids, or gases Share electrons Share electrons Can share more than 1 electron Can share more than 1 electron 2 main types: 2 main types:  Polar covalent bonds  Non polar covalent bonds

Polar Covalent Bonds Are when 2 different atoms share electrons, but the sharing is not equal Are when 2 different atoms share electrons, but the sharing is not equal This creates a dipole, a set of partial charges This creates a dipole, a set of partial charges

Non Polar Covalent Bonds Occur when electrons are shared equally Occur when electrons are shared equally It can happen between atoms of the same element or atoms of two different elements It can happen between atoms of the same element or atoms of two different elements

Double & Triple Covalent Bonds

Polyatomic Ions Are made of groups of covalently bonded atoms that have lost or gained electrons Are made of groups of covalently bonded atoms that have lost or gained electrons In other words, they have both ionic and covalent bonds In other words, they have both ionic and covalent bonds We use parentheses to group the atoms of a polyatomic ion We use parentheses to group the atoms of a polyatomic ion  (NH 4 ) 2 SO 4 The charge of a polyatomic ion applies to the entire ion The charge of a polyatomic ion applies to the entire ion