when they are bonded to other atoms
When do most atoms have lower potential energy?
attract
In the formation of a Covalent bond, the electrons of one atom and the protons of the other atom ______ one another?
repel
In the formation of a Covalent bond, Two Nuclei and two electrons ________ each other?
either positive or negative
The charge on an ion is….
lose two electrons
According to the octet rule, a calcium atom had a tendency to…
The compound contains just two atoms, each of opposite charge
If a compound forms by ionic bonding which is NOT true?
Lack of Crystal Structure
The only property listed that is NOT a characteristic of ionic compounds is….
a. high melting point
b. hardness
c. lack of crystal structure
d. brittleness
a. high melting point
b. hardness
c. lack of crystal structure
d. brittleness
sizes of the cations and anions, and the masses of the cation and anion
The crystal structure of an ionic compound depends on the…
attractive forces between ions are greater than the attractive forces between molecules
The melting points of ionic compounds are higher that the melting points of molecular compounds because…
share on or more pairs of electrons with each other
A covalent bond is formed when two atoms…
1.0
Two atoms will likely form a covalent bond if the electronegativity difference is…
resonance structures
Bonding in molecules or ions that cannot be represented adequately by a single Lewis structure is represented by…
covalent
As the electronegativity difference between bonded atoms decreases, the bonds become more…
water molecules are more polar and form hydrogen bonds
Why would the boiling point of water be higher than the boiling point of hydrogen sulfide?
decrease the potential energy, thus creating more stable arrangements of matter
As atoms bond with each other, they…
metallic
Which type of bonding is characterized by overlapping orbitals that allow outer electrons of atoms to move about freely throughout the entire lattice?
cations and anions
An ionic bond results from electrical attraction between…
electronegativity
A non polar covalent bond id unlikely when two atoms of different elements join because the atoms are unlikely to differ in…
their minimum potential energy
Bond length is the distance between two bonded atoms at…
which atoms are in the molecule, the number of valence electrons in each atom, the number of atoms in the molecule
To draw a Lewis structure, it is necessary to know these three things…
carbon, nitrogen, or oxygen
For multiple covalent bonds to form in molecules, the molecules must contain…
Octet rule
the principle states that atoms tend to form compounds in which each atom has eight electrons in its highest occupied energy level is called…
strength of an ionic bond
Lattice energy is an indication of the…
polar covalent bond
a covalent bond in which the bonded atoms have an unequal attraction for the shared electrons is called a______
diatomic molecule
A molecule containing two atoms is called a_________
electronegativity
the degree to which bonding between atoms of two different elements is ionic or covalent can be determined from the differences in the ___________of the element
molecule
A neutral group of atoms held together by covalent bonds is called a _________
chemical formula
A shorthand representation of the composition of a substance using atomic symbols and numerical subscripts is called an….
polyatomic ion
A charged group of covalently bonded atoms is called a __________
double bond
A covalent bond between two atoms produced by sharing two pairs of electrons is called a ________
formula unit
the simplest collection of atoms from which the formula of an ionic compound can be established is called a _________
bond energy
The energy required to break a chemical bond and form neutral isolated atoms is called __________
metallic bond
A chemical bond that results from the attraction between metal atoms and the surrounding sea of electrons is called _______
ductility
The property of being able to be drawn, puled, or etruded through a small opening to produce a wire is called_______
Ionic means atoms are given up, covalent means shared
Compare and contrast ionic and covalent bonding…
Most atoms are at lower potential energy when bonded to other atoms than they are as independent particles. Nature favors arrangements that lower potential energy.
why do most atoms from chemical bonds?
a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
What is a chemical bond?
As independent particles, most atoms are at a relatively high potential energy. Nature favors arrangements in which potential energy is lower. Atoms are less stable existing by themselves than when they are combined. By bonding with each other, atoms decrease in potential energy thereby creating more stable arrangements of atoms.
Why are most atoms chemically bonded to each other?
Ionic bonds and Covalent bonds
What are the two types of chemical bonds?
rare
Is it rare or common to have purely covalent or purely ionic bonds?
the measure of an atom’s ability to attract electrons
What is electronegativity?
electronegativities
The degree to which bonding between atoms is ionic or covalent can be estimated by calculating the difference in the elements’ _________
covalent
1.7 or < is _________
covalent
bonds between the same elements are_____
a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge.
What is a Non-polar-covalent bond?
non-polar-covalent
electronegativity 0-0.3
polar covalent
electronegativity 0.3-1.7
If the difference in electronegativity between the two atoms is greater than 1.7, then the bond is more ionic. If the difference in electronegativity between two atoms is less than 1.7, then the bond is more covalent.
How is electronegativity used in determining the ionic or covalent character of the bonding between two elements?
Ionic (H-2.1, F- 4.0— 4.0-2.1=1.9>1.7, so ionic)
Which type of bond would be expected from H and F?
Polar-Covalent (Cu-1.9, S-2.5—-2.5-1.9=1.4<1.7 so covalent, but 1.4>.3 so polar)
Which type of bond would be expected from Cu and S?
Polar Covalent (I-2.5, Br-2.8—2.8-2.5=0.3, so covalent, 0.3=0.3 so polar)
Which type of bond would be expected from I and Br?
I and Br, Cu and S, H and F
Our of H and F, Cu and S, and I and Br, order in increasing ionic character of bonding.
a chemical compound whose simplest units are molecules
What is a molecular compound?
indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts
What does chemical formula do?
the chemical formula of a molecular compound; shows the types and numbers of atoms combined in a single molecule of a molecular compound
What is a molecular formula?
the distance between two bonded atoms at their minimum potential energy (the average distance between two bonded atoms)
What is bond length?
Bond energy
What is the energy required to break a chemical bond and form neutral isolated atoms?
lone pair
pair of atoms that are not shared are often called…
unshared pairs
Structural indicated kind, number, arrangement, and bonds but not the ________
Double Covalent Bond
what is a covalent bond produced by the sharing of two pairs of electrons between two atoms?
Triple Covalent Bond
What is a covalent bond produced by the sharing of three pairs of electrons between two atoms?
increasing from single to double to triple
What order does bond energy go?
It gets shorter
As bond energy increases what happens to length?
some molecules and ions cannot be adequately represented by a single Lewis structure
When are resonance structures used?
bonding in molecules or ions that cannot be correctly represented by a single Lewis structure
What does resonance refer to?
ionic
Most rocks that make up earth’s crust are postive and negative ions held together by _______ bonding?
positive and negative ions that are combined so that the numbers of positive and negative charges are equal
What are ionic compounds composed of?
Crystalline solids
What do most ionic compounds exist as?
Crystal
What is a three-dimensional network of positive and negative ions mutually attracted to one another?
Nature favors arrangements with low potential energy, ionic crystal minimizes potential energy
What are characteristics of ionic bonds?
by combining into an orderly arrangement, crystal lattice
How does ionic crystal minimize potential energy?
those between oppositely charged ions and those between nuclei and electrons of adjacent ions
The attractive forces at work within an ionic crystal include…
those between electrons of adjacent ions
The repulsive forces include…
stronger
Attraction between adjacent oppositely charged ions is much ____than repulsion by other ions of the same charge, which are farther away
the energy released when one mole of an ionic crystalline compound if formed from a gaseous ions
What is lattice energy?
Molecular compounds
Which compounds melt at lower temperatures?
ionic compounds
which compounds have higher melting and boiling points?
slight shift of one row in ionic crystals cause buildup of repulsive forces, so its difficult to move one layer, makes them hard, if moves however, repulsion forces complete parting of layers
Why are Ionic compounds hard, but brittle?
Cannot
In solid state, ions can or cannot move?
can (conductors)
In molten state ions can or cannot move freely to carry electrical current?
a charged group of covalently bonded atoms
Polyatomic Ion
ions of opposite charge
Polyatomic ions combine with ___ to form an ionic compound
NaCl and CaF2
Give two examples of ionic compounds:
Ionic compounds consist of positive and negative ions bound together by electrical attraction. Molecular compounds are groups of atoms held together by covalent bonding, or the sharing of electrons.
How do you distinguish between ionic and molecular compounds in terms of the basic units that each is composed of?
they dont belong to any one atom but move freely about the metal’s network of empty atomic orbitals
What does delocalized mean?
