Chemistry Chpt. 12 Lecture

Front 1

Electrons found close to the nucleus is...

Back 1

Core electrons

Front 2

Electrons found in the most distant S and P energy subshells.

Back 2

Valence.

Front 3

Which electrons are responsible for holding two or more atoms together in a Chemical bond?

Back 3

Valence electrons form a chemical bond.

Front 4

The ___ ___ states that atoms bond in such a way so that each atom aquires 8 electrons in its outer shell.

Back 4

Octet rule.

Front 5

What are the two ways an atom may acheive an octet?

Back 5

1- By transfer of electons from one atom to another =
ionic bond

2- by sharing one or more pairs of electrons. =
covalent bond

Front 6

___ ____ are formed from the complete transfer of electrons between atoms to form ___ ___. bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.

Back 6

Ionic Bonds
bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.

Front 7

____ ____ are formed when two atoms share electrons to form molecular compounds (overlap).

Back 7

Covalent bonds.

Front 8

An ___ ___ is formed by the attraction between positively charged CATIONS and negatively charged ANIONS.

Back 8

Ionic bonds

This is similar to opposite poles on two magnets.
bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other.

Front 9

____ are formed when an atom loses valence electronsto become positively charged.

Back 9

Cations.
Cats lose electricity.

Front 10

____ are formed when an atom gains electrons and becomes negatively charged.

Back 10

Anions
are negative.

Onions make negative breath.

Front 11

The radius of a ___ is smaller than the radius of its starting atom.

Back 11

Cation.
Because it loses electrons thus becoming less mass.

Front 12

The radius of a ___ is larger than the radius of its starting atoms.

Back 12

Anion.
Because an Anion gains electrons thus the atoms becomes larger yet it is now negatively charged.

Front 13

___ ___ are formed when two "nonmetal" atoms share electrons and the shared electrons belong to both atoms.

Back 13

Covalent bonds.

Front 14

When a ___ ___ is formed the valence shells of the two atoms overlap with each other.

Back 14

Covalent bond

Front 15

The mixing of sublevels draws the ____ close to gether.

Back 15

Atoms.
Nucleus.

Front 16

___ is released when two atoms form a covalent bond.

Back 16

Energy.

Front 17

___ is needed to break covalent bonds.

Back 17

Energy.

Front 18

Energy required to break a covalent bond is referred to as ___ ___.

Back 18

Bond energy. The amount of energy to break a bond is the same to form one.

Front 19

The number of dots around each atom is equal to the number of ___ ___ the atom has.

Back 19

Valence electrons.

Front 20

A ___ ___ shows the bonds between atoms and helps us to visualize the arrangement of atoms in a molecule.

Back 20

Lewis structure.

Front 21

Calculating the total number of valence electons for a molecule is done by ....

Back 21

adding all of the valence electrons for each atom in the molecule then divide by 2 to find the total pairs.

Front 22

Electron pairs that are shared by atoms are called ___ ___. The other lectrons complete octets and are called ___ ___ or lone pairs.

Back 22

bonding electrons
nonbonding electrons.

Front 23

If there are not enough electron pairs to provide each atom with an octet, move a nonbonding electron pair between two atoms that....

Back 23

already share an electron pair.

Front 24

Electron dot formula for H2O:
First count the total number of valence electrons: oxygen has 6 and hydrogen has 1 for a total of 8; (6+2(1) = 8 electrons
There are two hydrogens so the formula displays 2 times the number of it's valence which is only 1 for hydrogen.

Back 24

Place 8 dots surrounding the central atom Oxygen.
Then place two hydrogen atoms in any of the four electron pairs positions thus displaying two bonding and two nonbonding pairs.

Front 25

Two shared electron pairs constitute a ___ ___.

Back 25

Double bond.

Front 26

The phenomenon of double bonding is called ____.

Back 26

Resonance.
Double bonding is resonance.

Front 27

Write the structural formula (Lewis structure) for HCN?

Back 27

1 + 4 + 5 = 10 e-
H + C + N =

Front 28

Write the structural formula for HCCH.
How many valence electrons in each then total them?

Back 28

1+4+4+1 = 10 e-
or
2(1) + 2(4) because there are two hydrogen and two Carbons. The one represents it's valence electrons for Hydrogen. The 4 represents the valence for Carbon.

Front 29

A ___ ___ ___ is one in which the electrons are not shared equally.

Back 29

polar covalent bond
Unlike nonpolar bonds where those have equal electronegativty.
polar - electrons aren't shared.
Nonpolare- equal electronega.

Front 30

____ is the ability of an atom to attract electrons in a chemical bond.

Back 30

Electonegativity.

Front 31

Electronegativity increases as you go ___ to ___ across a period and ___ to ___ in a family.

Back 31

Electronegativity increases
left to right
and
bottom to top within a family.

Front 32

A ___ ___written near a molecule indicates a polar bond.

Back 32

delta symbol
delta positive or negative

Front 33

If two atoms in a covalent bond have the same or similar electronegativities then the bond is not polarized and called a ___ ___ ___ if the electronegativity difference is greater than .5 and less than 1.8

Back 33

nonpolar covalent bond

Front 34

nonpolar covalent bond <.5
polar covalent bond .6 - 1.7
ionic bond >1.8

Back 34

nonpolar covalent bond <.5
polar covalent bond .6 - 1.7
ionic bond >1.8

Front 35

A covalent bond resulting from one atom donating a lone pair of electrons to another atom is called a ___ ___ ___.

Back 35

Coordinate covalent bond

Ozone is a good example.

Front 36

Oxygen is partially negative while Hydrogen is partially positive making it a ___ ___.
Any time Hydrogen is involved it's a ___ ___.

Back 36

Hydrogen bond.

Front 37

Electrons repel eachother and referred to as ____.

Back 37

Valence Shell Electron Pair Repulsion.
VSEPR theory

Front 38

A tetrahedral is what degrees apart?

Back 38

109.5 degrees
Methane is .

Front 39

With ammonia NH3,
Although the electron pair geometry may be tetrahedral the molecular shape is ___ ___.

Back 39

Trigonal Pyramidal.
107 degrees

Front 40

H2O is also tetrahedral and the molecular shape is ___.

Back 40

Bent at a
104.5 degree angle.
Note that they do NOT repel eachother like a linear does.

Front 41

CO2 has two oxygen atoms that equally repel one another thus causing a ___ ___.

Back 41

Linear molecule.

Front 42

Why is diamond colorless and hard while graphite is black and soft if both are pure carbon?

Back 42

Diamond has a 3d structure while graphite has a 2d structure.
Graphite can be flaked off in layers.