Lewis Dot Structure, EDG, MG, Electronegativity and Bond Polarity

Question 1

are diagrams that represent the valence electrons
of atoms within a molecule.

This help visualizes the valence electron/s of atoms and molecules, whether they exist as lone pairs or within bonds.

Answer 1

lewis/electron dot structure

Question 2

rule no. 1 in lewis dot structure

Answer 2

Finding the number of electrons available for distribution is done by adding the valence electrons of all the atoms in the molecule or polyatomic ion. For positively charged polyatomic ions, the numerical charge is deducted from the total valence electrons. For negatively charged ions, the numerical charge is added.

Question 3

rule no. 2 in lewis dot structure

Answer 3

In arranging the atoms, the least electronegative atom is assigned as the central atom. Hydrogen can form only one covalent bond so it is automatically designated as the terminal atom. Halogens are also usually assigned as terminal
atoms; but in cases, they serve as central atoms. When atoms are arranged, they are each connected by a single covalent bond first

• Each bond accounts for two electrons. To find the remaining electrons available for distribution, subtract those used for bonding from the total
  electrons computed in rule no. 1.

Question 4

rule no. 3 in lewis dot structure

Answer 4

The remaining electrons from rule no.2 are distributed to the atoms such that there are two electrons for hydrogen (satisfying the duplet rule) and eight electrons for the other atoms (satisfying
the octet rule).

Question 5

rule no. 4 in lewis dot structure

Answer 5

If there are not enough electrons for the atoms to have 8 electrons each, the single bonds are changed to double or triple bonds by shifting nonbonding pairs of electrons as needed

Question 6

rule no. 5 in lewis dot structure

Answer 6

If there are more than one Lewis structure that result in rule no. 4, the one that is symmetrical is usually chosen. The concept of formal charge also helps determine the acceptable Lewis structure.

Question 7

rule no. 6 in lewis dot structure

Answer 7

The structure of a polyatomic ion is enclosed in brackets and the charge is placed at the upper right corner of the bracket

Question 8

is the charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity. When determining
the best Lewis structure (or predominant resonance structure) for a molecule, the structure is chosen such that the this on each of the atoms is as close to zero as possible.

Answer 8

formal charge

Question 9

formula of formal charge

Answer 9

(no. of valence e-) minus (no. of unshared e-)
minus 1/2 (no. of shared e-)

Question 10

It refers to the tendency of atoms to prefer to
have eight electrons in the valence shell except
for hydrogen because it is stable with two
electrons (duplet rule).

When atoms have fewer than eight electrons, they
tend to react and form more stable compounds.

Answer 10

octet rule

Question 11

which sublevels are involved in the octet rule, making it useful for the representative
elements (Group A elements)

Answer 11

s and p sublevels

Question 12

bonds with complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions, one is the electron donor (cation/metal) and the other is the electron acceptor (anion/nonmetal).

Answer 12

ionic bonds

Question 13

bonds with sharing of electrons between atoms. This type of bonding occurs between two atoms of the same element (diatomic molecule) or of elements with the same electronegativity. This bonding occurs primarily between nonmetals; however, it can also be observed between cations/metals and anions/nonmetals. (e.g.
binary acids)

Answer 13

covalent bonds

Question 14

special type of ionic compound that are covalently bonded since hydrogen acts as a cation/metal
(+1) when reacting with an anion/nonmetal

Answer 14

binary acids

Question 15

The arrangement of electron pairs around a
central atom

• In determining the shape, it takes into account
  the presence of both bond pair(s) and lone
  pair(s) of electrons.
• Number of total electron pairs are calculated.

Answer 15

electron domain geometry

Question 16

The arrangement of atoms in a molecule, usually
relative to a single central atom

• It excludes lone pairs from determining a
  molecule’s shape, though repulsion from lone
  pair(s) is taken into account only in bond
  angles.
• Number of bonding pairs are only calculated.

Answer 16

molecular geometry

Question 17

we can use the ______________ and the ________________________ when writing for the molecular geometry of a molecule or a compound.

Answer 17

Lewis structure, Valence Shell Electron Pair Repulsion (VSEPR) theory

Question 18

a model used to predict 3-D molecular geometry based on the number of valence shell electron bond pairs among the atoms in a molecule
or ion. This model assumes that electron pairs will arrange themselves to minimize repulsion effects from one another. In other words, the electron pairs are as far apart as possible.

Answer 18

Valence Shell Electron Pair Repulsion (VSEPR) theory

Question 19

In showing the bonds of a molecule, the ______ represents the flat on the paper position while the __________ is the one facing the
observer. The _________ is the one at the back.

Answer 19

line, solid wedge, dashed wedge

Question 20

________ of an atom play(s) an important role
in the molecular geometry of a compound. They/it
occupy specific orbitals in the atoms, as they/it
increase the repulsion and decrease the bond angle.

Answer 20

lone pair

Question 21

AX2

Answer 21

EDG: Linear
Mg: Linear

Question 22

AX3

Answer 22

EDG: Trigonal Planar
Mg: Trigonal Planar

Question 23

AX2E1

Answer 23

EDG: Trigonal Planar
Mg: Bent

Question 24

AX4

Answer 24

EDG: Tetrahedral
Mg: Tetrahedral

Question 25

AX3E1

Answer 25

EDG: Tetrahedral
Mg: Trigonal Pyramidal

Question 26

AX2E2

Answer 26

EDG: Tetrahedral
Mg: Bent

Question 27

AX5

Answer 27

EDG: Trigonal Bipyramidal
Mg: Trigonal Bipyramidal

Question 28

AX4E1

Answer 28

EDG: Trigonal Bipyramidal
Mg: Seesaw

Question 29

AX3E2

Answer 29

EDG: Trigonal Bipyramidal
Mg: T-Shaped

Question 30

EX2E3

Answer 30

EDG: Trigonal Bipyramidal
Mg: Linear

Question 31

EX6

Answer 31

EDG: Octahedral
Mg: Octahedral

Question 32

EX5E1

Answer 32

EDG: Octahedral
Mg: Square Pyramidal

Question 33

EX4E2

Answer 33

EDG: Octahedral
Mg: Square Planar

Question 34

a measure of an atom’s ability
to attract shared electrons to itself.

Answer 34

electronegativity

Question 35

On the periodic table, electronegativity generally
__________ as you move from left to right across a
period and _____________ as you move down a group.

Answer 35

increases, decreases

Question 36

• Electronegativities can be used to predict the nature of the chemical bond that can exist between atoms.
• The larger the electronegativity difference ( EN)
  between the atoms, the _______ the bond will be.
• ___________ have the highest EN and are therefore the most polar of the chemical bonds.
• _____________may be polar or nonpolar depending on the electronegativities of the atoms involved.

Answer 36

more polar; ionic; covalent bonds

Question 37

electronegativity difference greater than or equal to 1.7

Answer 37

ionic bonds

Question 38

END greater than 0.4 but less than 1.7

Answer 38

polar covalent bonds

Question 39

END less than or equal to 0.4

Answer 39

non-polar covalent bonds

Question 40

Two atoms with equal electronegativities equally
share the electrons, which results in an even
electron density. This produces a ________________

Answer 40

non-polar bond

Question 41

Unequal electronegativities result in an uneven electron distribution in a bond, with one partially positive end and one partially negative end. The resulting bond is described as ______

Answer 41

polar

Question 42

• The charge separation resulting from the unequal sharing of electrons is known as __________ represented as arrows where the arrowhead points the more electronegative atom.
• The greater the electronegativity difference between the bonded atoms, the greater it is

Answer 42

bond dipole

Question 43

A polar covalent molecule always contains one or
more polar bonds, but some molecules with polar
bonds can be nonpolar overall.
- This difference can be explained by the _____________ (molecular dipole) measured in debyes and which is affected by the shape of the molecule

Answer 43

net dipole moment

Question 44

The polarity of substances determines their
solubility in different solvents.
Solubility follows the general rule “like dissolves
like,” which pertains to the similarity of the
polarity of the solute and the solvent. A nonpolar
(or polar) solute _______ dissolve in a polar (or
nonpolar) solvent.

Answer 44

will not