Chapter 8

Question 1

Chemical bond meaning

Answer 1

strong attractive force between certain atoms in a substance

ionic bonds (electron transferred)
covalent bonds (electrons shared EQUALLY, unless polar)
metallic bonds

Question 2

Bond lenght meaning

Answer 2

as 2 atoms (of hydrogen hypothetically) get closer, the energy decreases to a minimum, then goes up drastically. The minimum is called bond lenght

Question 3

Polar covalent bonds meaning

Answer 3

unequal sharing of electrons, electrons near one atom more, the most electronegative
results in a chage seperation in the bond (one side positive, one negative (diople moment))

Question 4

Electronegativity

Answer 4

Ability to attrack electrons to itself when in a covalent bonds
increases from left to right, from down to up (top right most electronegative)
Fluorine most electronegtaive with 4, cesium and francium leas with 0.7

when difference in electronegativity very big between bonding atoms, ionic
when medium, polar covalaent bond
when small, non polar covalent

Question 5

Dipole moment representation

Answer 5

represent with an arrow poini\ting towards negative charge
most electronegative is the negative

Question 6

Isoelectronic

Answer 6

Series of atoms/ ions having the same number of electrons

Question 7

Lewis structure

Answer 7

central atom is least electronegative
Carbon always central
H and F never central

Question 8

Octet rule exceptions

Answer 8

H always 2 electrons
Be always 4 electrons
B, Al, Sn always 6 electrons
C, N, O, F, always 8 electrons
all others can have more then 8 because d orbital now open after 3s is reached

Question 9

resonance

Answer 9

Actual structure is average of resonnance structure
Electrons are delocalized and can move around entire molecule
When double or triple bond, it is present between every option at all times. Draw all options with arrows between

Question 10

VSEPR

Answer 10

electrons are as far away as possible from one another because they repel

Question 11

Arrangement of pairs

Answer 11

2 pairs: linear 180*
3 pairs: trigonal planar 120*
4 pairs: tetrahedral 109.5*
5 pairs: trigonal bipyramidal 90* and 120*
6 pairs: octahedral 90*

Question 12

Molecular geometry: 2 pairs

Answer 12

Linear

Question 13

Molecular geometry: 3 pairs

Answer 13

Trigonal planar (AX3)
with 1 lone pair Bent/angular (AX2) (polar)

Question 14

Molecular geometry: 4 pairs

Answer 14

Tetrahedral (AX4)
1 lone pair, trigonal pyramidal (AX3) (polar)
2 lone pairs, bent/ angular (AX2) (polar)

Question 15

Molecular geometry: 5 pairs

Answer 15

Trigonal bypriamidal (AX5)
1 lone pair, from the side, Seesaw/distprted tetrahedron (AX4) (polar)
2 lone pairs, from the side, ST shaped (AX3) (polar)
3 lone pairs, from the side, Linear, (AX2)

Question 16

Molecular geometry: 6 pairs

Answer 16

Octahedral (AX6)
1 lone pair, from top, Square pyramidal (AX5) (polar)
2 lone pairs, from top and bottom, square planar, (AX4)

Question 17

Formal charge formula

Answer 17

Valence -bonding pairs - lone electrons

best is with the FC closest to zero