Chemical bonding, Ionic Bonds, Covalent Bonds Flashcards
tend to have high melting points (500°C–2000°C) and are good conductors of electricity when they are in a molten (liquid) state or in solution. NET CHARGE MUST BE 0
ionic compounds
generally have much lower melting points and tend to be gases, liquids, or low melting-point solids. They do not conduct electricity in the molten state.
molecular compounds
do not have molecules as their basic structural unit. Instead, an extended array of positively and negatively charged particles called ions is present.
ionic compounds
ionic compounds do not have molecules as their basic structural unit. Instead, an extended array of positively and negatively charged particles called ___ is present.
ions
What determines whether the interaction of two elements produces ions (an ionic compound) or molecules (a molecular compound)?
chemical bonds
attractive force that holds two atoms together in a more complex unit . form as a result of interactions between electrons found in the combining atoms.
chemical bonds
chemical bond formed through the transfer of one or more electrons from one atom or group of atoms to another atom or group of atoms. ionic compounds are present
ionic bonds
chemical bond formed through the sharing of one or more pairs of electrons between two atoms. molecular compound is present
covalent bond
the chemical symbol of an element surrounded by dots equal in number to the number of valence electrons present in atoms of the element. (number of valence electron = group number)
lewis symbol
Not all electrons in an atom participate in bonding. Those that do are called___. an electron in the outermost electron shell of a representative element or noble-gas element.
valence electron
Lewis symbols, named in honor of the American chemist _____ who first introduced them, are also frequently called electron-dot structures.
Gilbert Newton Lewis
considered the most stable of all valence electron configurations, loose gain or share to produce noble gas
octet rule
does not have outermost s& p subshell completely filled, only 1s2
helium
most unreactive of all the elements. They are the only elemental gases found in nature in the form of individual uncombined atoms.
noble gases
lose electrons to form cations
metals
gain electrons to form anions
nonmetals
opposite attract
electrostatic attraction
forces that hold groups of atoms together and make them function as unit
bond
form solid crystals at ordinary temp, organize crystal lattice of alternate positive and negative
ionic compound
ALL SALTS ARE
ionic compound and form crystal
properties of ionic compounds
crystalline solids, high melting and boiling point, excellent conductors and soluble in water
metals, cation +
Li, Na, K
metals, cation, 2+
Mg, Ca, Ba
metals cation 3+
Al
nonmetals anion -
F, Cl, Br, I
nonmetals anion 2-
O, S
nonmetals anion 3-
N, P
Involve sharing outer energy level electrons
covalent bonds
work by electromagnetic attraction. A positively charged ion is attracted to a negative ion.
ionic bonds
work by sharing electrons. They do not have charges, but are hard to separate due to this sharing.
covalent bonds
no H
lone pair
with H
single pair
_____do not form covalent bonds!
alkali and alkaline
covalently bonded
halogens, non-metals in group 3,4,5,6
single electrons is =
bonds
Why do electrons first fill orbitals
one at a time before pairing up?
It is because electrons repel each other and want to be as far apart as possible.
exception to octet
3 valence electrons or below, so it is impossible to get to eight via covalent bonding
can be defined as the attractive forces which hold different constituents (ions, atoms, etc.) together in different chemical species.
chemical bonds
When two atoms share one electron pair between each other, then they are said to be bonded by ____ denoted by single dash joining the atoms.
single bond
When two atoms share two electron pairs between each other, they are said to be bonded by denoted by double dash joining the atoms.
depicted as two parallel lines (=)
double bond
When two atoms share three electron pairs with each other, they are said to be bonded by triple covalent bond. Triple bond is denoted by three dashes joining the atoms.
triple bond
quadruple bonds?
cannot occur, because the last bond can not bend all the way around
-the nuclei of various elements have differing abilities to attract shared electrons (in a bond) to themselves.
-Some elements are better electron attractors than other elements.
- measure of the relative attraction that an atom has for the shared electrons in a bond.
electronegativity
higher the electronegativity value for an element
he greater the attraction of atoms of that element for the shared electrons in bonds.
whose contributions to chemical bonding theory earned him a Nobel Prize in chemistry, was the first chemist to develop a numerical scale of electronegativity.
Linus Pauling
greater electronegativity (increases)
going to right, going up
When two atoms of equal electronegativity share one or more pairs of electrons, each atom exerts the same attraction for the electrons, which results in the electrons being equally shared. SYMMETRICAL. This type of bond is called
nonpolar covalent bond
When the two atoms involved in a covalent bond have different electronegativities, the electron-sharing situation is more complex. The atom that has the higher electronegativity attracts the electrons more strongly than the other atom, which results in an unequal sharing of electrons. ASYMMETRICAL. This type of covalent bond is called
polar covalent bond
measure of the degree of inequality in the sharing of electrons between two atoms in a chemical bond.
bond polarity
to get polarity
get the electronegativity difference (EN= EN(higher) - EN (lower)
The greater the numerical difference
the greater the inequality of electron sharing and the greater the polarity of the bond.
the existence of bond polarity means that
there is no natural boundary between ionic and covalent bonding. Most bonds are a mixture of pure ionic and pure covalent bonds; that is, unequal sharing of electrons occurs.
Bonds that involve atoms with the same or very similar electronegativities are called ___ “Similar” here means an electronegativity difference of 0.4 or less.
nonpolar covalent bonds
Bonds with an electronegativity difference greater that 0.4 but less than 1.5 are called
polar covalent bonds
Bonds with an electronegativity difference greater than 2.0 are called
ionic bonds
Bonds with an electronegativity difference between 1.5 and 2.0 are considered____ if the bond involves a metal and a nonmetal, and polar covalent if the bond involves two nonmetals.
ionic
ionic if metal is present and polar covalent when only nonmetals are present
ionic or polar covalent
very unequal sharing of electrons (electron transfer)
ionic
