Honors Chemistry Chapter 7 - Ionic and Metallic Bonding

subatomic particle that plays the most important role in chemical bonding

electrons

chemical bond

force of attraction between two atoms

most important types of electrons in chemical bonding

valence electrons

Lewis symbols

shorthand notations used to represent the valence electrons in an element

how an atom can become an ion

losing or gaining electrons

cations

atoms that have lost electrons

charge of cations

positive

anions

atoms that have gained electrons

charge of anions

negative

how atoms form ions

in a way that they achieve a noble-gas like electron configuration

how metallic elements from ions

losing electrons

how nonmetallic elements form ions

gain electrons

octet rule

elements tend to lose, gain, or share electrons in a way that completes their outer shell of electrons with 8 valence electrons.

ionic bonds

formed by the transfer of electrons

formation of an ionic bond

exothermic

how cations and anions are held together in an ionic bond

electrostatic bond; they are opposites, so they are attracted to each other

formula unit

the simplest whole-number ratio of ions in an ionic compound. It is the smallest component of an ionic compound that retains the properties of that ionic compound.

charge formed by an ionic bond

0

crystal lattice

the three-dimensional structure of cations and anions.

lattice energy

the energy required to break the crystal lattice and separate the cations and anions

type of energy needed to break crystal lattice

endothermic energy

factors that affect the amount of lattice energy an ionic compound has

magnitude of the charge of the ions and overall size of the ions

melting and boiling points of ionic compounds

high

why ionic compounds have high melting and boiling points

strong electrostatic force between cations and anions

hardness of ionic compounds

very hard

why ionic compounds have such a high hardness

a great deal of electrostatic force is needed to separate the attraction between cations and anions

conductivity of ionic compounds

do not conduct electricity as solids, but can conduct electricity in molten phase or when dissolved, as they can freely carry electric charge

solubility of ionic compounds

dissolve extremely well in water

why ionic compounds dissolve so well in water

water molecules are polar and help attract cations and anions

electronegativity

the tendency of an atom to attract electrons towards itself

electronegativity in ionic bonds

ionic bonds result when the electronegativity difference between two elements is extremely high

combination of elements that results in an ionic bond

a metal and a nonmetal

ionization energies and electronegativity of metals

extremely low

valence band theory

metals have some overlap between the conduction band and the valence band of orbitals, which allows the freedom of movement of electrons between atoms.

sea of electrons model

describes metals as a lattice of cations immersed in a sea of valence electrons

how metal atoms are organized as solids

organized in a crystal lattice that resembles the arrangement of ionic solids.

alloys

solid, homogeneous mixtures of metallic elements with at least one other element.

advantages of alloys

alloys often improve or change the properties of the individual, often stronger or more resistant to rusting, made to have a higher (or lower) melting point, and sometimes they are cheaper than the pure metal.

substitutional alloys

alloys where the alloy components have similar atomic radii and can occupy the same spaces as their counterpart.

interstitial alloys

alloys where an element with a much smaller atomic radius can fit between empty spaces in the crystal lattice and help restrict movement.

luster of metals

incoming photons polarize the sea of electrons, which causes incoming light to be reflected instead of absorbed.

conductivity of metals

metals can conduct electricity very easily because of the mobility of electrons in the sea.

ability of metals to transfer heat

can also transfer heat energy very easily through vibrations.

mealleability of metals

very malleable

why metals are so malleable

metal cations can roll past one another very easily in the sea of electrons

melting point of metals

very high

why metals have such high melting points

it is very hard to separate metal cations completely from the electron cloud.