M2 C5 Electrons and bonding

Question 1

what is the number of electrons that can fill the first four energy levels

Answer 1

1- 2
2- 8
3- 18
4- 32

Question 2

what is the principal quantum number

Answer 2

the energy level number

Question 3

what is an orbital

Answer 3

a region around the nucleus that can hold up to 2 electrons with opposite spins

Question 4

what shape do s subshells make

Answer 4

circle (O)

Question 5

what shape do p subshells make

Answer 5

figure of eight (8)

Question 6

• How many orbitals are in a s sub shell

- How many electrons can it hold

Answer 6

1

- 2 electrons

Question 7

• How many orbitals are in a p sub shell

- How many electrons can it hold

Answer 7

3

- 6 electrons

Question 8

• How many orbitals are in a d sub shell

- How many electrons can it hold

Answer 8

5

- 10 electrons

Question 9

• How many orbitals are in a f sub shell

- How many electrons can it hold

Answer 9

7

- 14 electrons

Question 10

Which subshell fills up before 3d

Answer 10

4s (1st in and 1st out)

Question 11

what is an ionic bond

Answer 11

the electrostatic force of attraction between oppositely charged ions

Question 12

describe the structure of ionic compounds

Answer 12

form giant ionic lattices, resulting from oppositely charged ions strongly attracted in all directions

Question 13

describe the solubility of ionic compounds

Answer 13

often high if the attraction for water molecules is enough to over come the attraction between the ions

Question 14

describe the electrical conductivity of ionic compounds

Answer 14

only if molten or aqueous as the ions are free to move and carry the charge
(no mobile charge is carried in solid ionic compounds)

Question 15

describe the melting and boiling points of ionic compounds

Answer 15

they are high, it takes a lot of energy to overcome the strong electrostatic force of attraction between the ions to separate them

Question 16

what is a covalent bond

Answer 16

the strong electrostatic force of attraction between a bonded pair of electrons and the nuclei of the bonded atoms

Question 17

what is a dative covalent bond

Answer 17

a shared pair of electrons in which both electrons come from the same atom

Question 18

Electron pair repulsion theory

Answer 18

• electron pairs repel each other so they are as far apart as possible
• lone pairs repel more than bonded pairs
  (determines the shape of a molecule)

Question 19

each lone pair decreases a bond angle by about

Answer 19

2.5 degrees

Question 20

what is the shape (and angle) of a molecule with 2 pairs of electrons

Answer 20

linear (180)

Question 21

what is the shape (and angle) of a molecule with 3 pairs of electrons

Answer 21

trigonal planar (120)

Question 22

what is the shape (and angle) of a molecule with 4 bonding pairs of electrons

Answer 22

tetrahedral (109.5)

Question 23

what is the shape (and angle) of a molecule with 4 pairs of electrons but 1 pair is non bonding

Answer 23

pyramidal (107)

Question 24

what is the shape (and angle) of a molecule with 4 pairs of electrons but 2 pairs are non bonding

Answer 24

non-linear (104.5)

Question 25

what is the shape (and angle) of a molecule with 5 pairs of electrons

Answer 25

trigonal bypyramidal (90,120)

Question 26

what is the shape (and angle) of a molecule with 6 pairs of electrons

Answer 26

octahedral (90,180)

Question 27

what is the bond angel for - CH4 - NH3 - H2O

Answer 27

CH4 - 109.5 NH3 - 107 H2O - 104.5

Question 28

define electronegativity

Answer 28

the ability of an atom to attracted the bonded electrons in a covalent bond

Question 29

what is an intermolecular force

Answer 29

weak interactions between dipoles

Question 30

when describing the shape of a molecule...

Answer 30

work out number of bonded pairs then number of lone pairs

Question 31

what are the three types of intermolecular forces

Answer 31

- induced dipole-dipole interactions (london forces) - permanent dipole-dipole interactions - hydrogen bonding

Question 32

when are london forces (induced dipole-dipole interactions) present in a molecule - van der waal's interactions

Answer 32

- in polar molecules - in non polar molecules - in molecules with an H attached to a very electronegative atom

Question 33

when are permanent dipole-dipole interactions present in a molecule - van der waal's interactions

Answer 33

- in polar molecules

Question 34

when is hydrogen bonding present

Answer 34

- in molecules with an H attached to a very electronegative atom - eg. (O-H / N-H / F-H)

Question 35

what does the strength of london forces between molecules depend on

Answer 35

- the number of electrons involved | +electrons... larger dipole... stronger attractive force between molecules

Question 36

what is the effect of stronger london forces on the mp/bp

Answer 36

- more energy is need to overcome the london forces