Chemical Bonding

What are cations?

Positively charged because they have fewer e- than p+

Smaller than neutral atoms because increased attraction to the nucleus, e- pulled in closer

What are anions?

Negatively charged because they have more e- than p+

Larger than neutral atoms because they increased repulsion between e-

What is a general description of metallic bonding?

• metallic elements are held together by metallic bonding which results in metallic lattices

• The metal ions are surrounded by a sea of mobile electrons

• Present in alloys

What are physical properties of metallic bonding?

• Conduct electricity

• High mp/bp

• High thermal conductivity

• Malleability

• Luster

What is a general description of covalent bonding?

• The sharing of a pair of electrons between two atoms

• Each atom contributes, one electron to each bond

• Between nonmetal and nonmetal compounds

• Results in simple molecules or giant molecular lattices

What are physical properties of Covalent bonding?

• Often liquids or gases at room temperature

• Low mp/bp

• Soluble in organic solvents

• Do not conduct electricity

What Is a general description of ionic Bonding?

• Metal atoms transfer e- to nonmetal

• Metal atoms lose their outer electrons to become positive ions

• Nonmetals gain electrons to become negative ions (except hydrogen)

• result from the attraction between oppositely charged ions

What are physical properties of ionic bonding?

• they are crystalline solids at room temperature

• High mp/bp

• Often soluble in water

• Conduct electricity when molten or dissolved in water (not when solid)

What are crystalline solids?

a solid in which the particles are arranged in a regular repeating three-dimensional lattice, giving it a definite internal structure

What are physical properties of graphite?

• Each C is only bonded to three other C atoms to make C rings that arrange in layers/sheets

• Soft, layers slide off

• Conduct electricity because only three of the four valence e- are involved in bonding

• The last electron is ‘’free’’ or delocalized

What are allotropes?

Two or more different forms of an element in the same physical state of matter, but having different molecular arrangements and so having different physical properties

What are the physical properties of diamond?

• Each carbon atom is attached to 4 others

• Tetrahedral hardest neutral substance

• Very high melting point

• Very hard

• Rigid bonds and more brittle than giant metallic lattices

• Does not conduct electricity because all four valence e- are bonded

What are alloys?

A mixture of two or more elements with at least one as a metal

Why are alloys generally stronger than their pure metal counterpart?

• When the medals are mixed together, their strengths and densities combined making them greater

• The different size atoms cannot slip over each other and disrupt the lattice

What are some bonding rules?

• Hydrogen and hydrogen only bond once one single bond

• Oxygen must bond twice

• Nitrogen must bond three times

• Carbon must have four bonds

What are simple covalent structures and giving an example?

• Covalent

• They are simple molecular

• Have a low mp/bp

• H2O

What are giant molecular structures and give an example?

• Covalent

• Stronger

• High mp/bp

• Repeating lattices

• Diamond and graphite

• Diamond is tetrahedral doesn’t conduct electricity

• Graphite is 3 C atoms, layers, no co bonds between layers, conduct electricity, and heat

What is giant ionic bonding and given an example?

• Metal to nonmetal

• High mp/bp

• Hard and brittle

• Crystalline solids at room temperature

• Conduct electricity and heat when molten or dissolved in H2O

• It is the biggest

• Salt; NaCl

What is a giant metallic structure and given an example?

• Metallic bonding

• High bp/mp

• Conduct electricity and heat

• Delocalized e-

• Malleable

• Alloys

• Ag and Silver

What is a monoatomic structure and given an example?

• It is by itself

• Full outer shell of e-

• Low mp/bp

• Ne

What is a saturated molecule?

• Only single bonds between carbon atoms

• Alkanes are saturated

What is an unsaturated molecule?

• there is one or more double or triple bonds C=C

• Alkenes are unsaturated

What is the definition of a homologous series?

A family of organic compounds that;

• Have similar chemical properties

• Have the same general formula

• Show gradual increase in physical properties such as mp/bp

What are alcohols and what is the general formula?

A series of organic compounds containing The functional group -OH and with the general formula CnH2n+1OH

What are carboxylic acids?

A hydrocarbon with a carbonyl group with a OH bonded to it -COOH

What is a carbonyl ?

C double bonded to an O