Section 9.1- Types of Chemical Bonds Flashcards
is composed of two or more elements that have combined chemically
compound
is an attractive force between atoms that is strong enough to enable the group to act as a unit
chemical bond
simple ionic compounds and molecular compounds typically have very __________________ properties
different
the most important factor affecting how atoms form chemical bonds is the
number of valence electrons in each atom involved
the principle that states that the atoms will tend to react chemically so as to achieve a noble-gas electron configuration, either by losing or gaining electrons or by sharing electrons with other atoms, therefore obtaining additional stability
octet rule
ionic bonding is literally the
“transfer” of electrons
as a rule, elements toward the ______________ of the periodic table tend to lose electrons in bonding, while elements toward the __________ of the periodic table tend to gain electrons in bonding
left- lose
right- gain
atoms that gain electron become
anions
atoms that lose electrons become
cations
a chemical bond in which positively charged ions are electrically attracted to negatively charged ions is an
ionic bond
ionic compounds do not consist of
molecules
the elements on the left side of the periodic table (metals) react with elements on the _____________________________ to form ionic crystalline solids
far right side (nonmetals)
a chemical bond that results from the SHARING of valence electrons between atoms is a
one atom is bonded to the other because both are attracted to the electrons shared between them
covalent bonds
________________________ of both positive nuclei for the negatively charged electron cloud holds the nuclei together in a covalent bond
mutual attraction
all _______________ are identical
electrons
when two atoms share a single pair of electrons the bond is a
single covalent bond (single bond)
two or three pairs of electrons shared by two atoms form a
multiple bond
sharing two pairs of electrons forms a
double bond
sharing three pairs of electrons
triple bond
some compounds, especially those containing _________________, include both ionic and covalent bonds
polyatomic ions
pairs not involved in a bond
lone pairs or nonbinding pairs
generally, covalent bonds hold atoms discrete molecules that contain a ______________ number of atoms and have specific _______________
fixed number
geometric shapes
substances that are composed of billions or trillions of atoms that are bonded together into a singe unit by a strong covalent bonds
covalent networks
the hardest known substance composed of a three dimensional network (crystal)
diamond
extremely large molecules
macromolecules
all metals share these similar properties
- good conductors of electricity
- good conductors of heat
- malleable and ductile
- most are shiny and highly reflective
- have very high melting and boiling points
chemical bonds that bind atoms together in a metal are
metallic bonds
when an electron is shared not with just one nearby atom but with all the surrounding atoms, they are called
delocalized electrons
the large number of freely circulating _____________ gives metals their characteristic properties
electrons
in most cases, the bonding in compounds is not completely ______________________________
ionic, covalent, or metallic
a bond is considered predominantly ionic if the electronegativity difference between the two bonded atoms is greater than
1.7
if the difference of the atoms in a bond is less than 1.7, the bond is predominantly
covalent
a covalent bond in which both atoms share electrons equally is a
nonpolar bond
a covalent bond in which electrons are shared unequally between atoms is a
polar bond (unequal sharing)
is only a fraction of a “full” charge such as 1+ and 1-
represented by the lowercase Greek letter delta
partial charge
a bond or molecule that has a negative end and a positive end (a polar bond or polar molecule) forms a
dipole
a dipole is represented by
|——-> (points toward the more electronegative end)
