Electrons, Bonding And Structure

Question 1

How many orbitals does an S sub-shell have? And therefore what is the maximum number of electrons?

Answer 1

1 orbital
Maximum of 2 electrons

Question 2

How many orbitals does an P sub-shell have? And therefore what is the maximum number of electrons?

Answer 2

3 orbitals
6 electrons maximum

Question 3

How many orbitals does an D sub-shell have? And therefore what is the maximum number of electrons?

Answer 3

5 orbitals
10 electrons maximum

Question 4

How many orbitals does an F sub-shell have? And therefore what is the maximum number of electrons?

Answer 4

7 orbitals
14 electrons maximum

Question 5

What is the total number of electrons on each shell?

Answer 5

1st = 2
2nd = 8
3rd = 18
4th = 32

Question 6

What shape do p-orbitals have?

Answer 6

Dumbbell shape

Question 7

What shape do S-orbitals have?

Answer 7

Spherical

Question 8

What is an orbital?

Answer 8

A region of a sub-shell that contains a maximum of 2 electrons with opposite spins

Question 9

Which sub-shell doesn’t follow the expected order? Why?

Answer 9

4s comes before 3d
4s has a lower energy level than 3d so fills up first

Question 10

What is an ionic bond? Is it strong or weak?

Answer 10

An electrostatic attraction between 2 oppositely charged ions - very strong

Question 11

Do ionic compound conduct electricity?

Answer 11

Yes when molten or dissolved as the ions in a liquid are free to move and carry a charge.

Question 12

What are the melting and boiling points like in an ionic compound?

Answer 12

High melting and boiling points as the giant ionic lattices are held together by strong electrostatic forces which take a lot of energy to overcome

Question 13

Are ionic compound soluble?

Answer 13

Tend to dissolve in water. Water molecules are polar so can pull ions away from the lattice and cause it to dissolve.

Question 14

What is a covalent bond?

Answer 14

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

Question 15

What is dative covalent bonding? What is another name for this?

Answer 15

Where one of the atoms provides both of the shared electrons also known as coordinate bonding. E.g. NH4 +

Question 16

Draw boron trifluoride

Answer 16

3 pairs of shared electrons (covalent bonding) on the boron (1 for each F atom). Only 6 electrons on outer shell of boron. 8 electrons on outer shell of each fluorine

Question 17

Draw sulfur hexafluoride. Why is this possible?

Answer 17

Sulphur covalently bonded to 6 fluorine atoms. Shared pair of electron between sulphur and each fluorine. 12 electrons on outer shell of sulphur.
A few compounds can use d-orbitals to ‘expand the octet’

Question 18

What affects the strength of a covalent bond?

Answer 18

How much the outer atomic orbitals of the bonded atoms overlap
How strongly the atomic nuclei are attracted to the shared electrons

Question 19

What is average bond enthalpy?

Answer 19

The energy needed to break one mole of a bond in the gas phase, averaged over the different compounds that the bond is found in.

Question 20

What are lone pairs?

Answer 20

Pair of unshared electrons

Question 21

What is electron shell repulsion theory?

Answer 21

The theory that in a molecule lone pair/lone pair bond angles are the biggest, lone pair/bonding pair bond angles are second biggest and bonding pair/bonding pair bond angles are the smallest.

Question 22

How do you draw which way bonds are pointing?

Answer 22

Broken line - bond pointing away from you
Wedge - bond pointing towards you
Line - in plane of the page

Question 23

2 electron pairs shape: name and bond angle?

Answer 23

Name: linear
Bond angle: 180

Question 24

Do double bonds change bond angles?

Answer 24

No

Question 25

2 electron pairs and 2 lone pairs shape: name & bond angle?

Answer 25

Name: non-linear
Bond angle: 104.5

Question 26

3 electron pairs shape: name, bond angle, drawing?

Answer 26

Name: trigonal planer
Bond angle: 120
Drawing: 3 lines from central atom

Question 27

4 bonding pairs shape: name, bond angle and drawing?

Answer 27

Name: tetrahedral
Bond angle: 109.5
Drawing: 2 lines, 1 wedge, 1 broken line

Question 28

3 bonding pairs and 1 lone pair shape: name, bond angle and drawing?

Answer 28

Name: trigonal pyramidal
Bond angle: 107
Drawing: 1 lone pair, 1 broken line, 1 wedge, 1 straight line

Question 29

5 bonding pairs shape: name, bond angles, drawing?

Answer 29

Name: trigonal bipyramidal
Bond angles: 120 and 90
Drawing: 3 straight lines, 1 broken line, 1 wedge (3 atoms in trigonal planer shape with bond angles of 120, other 2 atoms at 90 to them

Question 30

6 bonding pairs shape: name, bond angle, drawing?

Answer 30

Name: octahedral
Bond angle: 90
Drawing: 2 straight lines, 2 broken lines, 2 wedges