Chapter 5: Electrons and bonding

Question 1

What are electron shells?

Answer 1

Shells can be regarded as energy levels for electrons where energy increases in accordance to a shells principle quantum number.

Question 2

What are orbitals?

Answer 2

Regions around a nucleus where a pair of electrons with alternate spins are likely to reside.

Question 3

How many electrons can be held in an orbital?

Answer 3

2 of alternate spin

Question 4

What are the 4 key types of orbital

Answer 4

S, P, D & F

Question 5

What is the S- orbital?

Answer 5

A spherical region around the nucleus; present at all energy levels, 1 per level.

Question 6

What is the P- Orbital?

Answer 6

A dumbbell shaped region; present at energy level 2 and up, 3 per level in the X, Y, Z plane.

Question 7

What is the D- orbital?

Answer 7

A dumbbell shaped region; present at energy level 3 and up, 5 per level

Question 8

What is the F- orbital?

Answer 8

A dumbbell shaped region; present at energy level 4 and up, 7 per level in the X, Y, Z plane.

Question 9

What is the maximum number of electrons in shell 1?

Answer 9

2

Question 10

What is the maximum number of electrons in shell 2?

Answer 10

8

Question 11

What is the maximum number of electrons in shell 3?

Answer 11

18

Question 12

What is the maximum number of electrons in shell 4?

Answer 12

32

Question 13

What are the maximum number of electrons in each subshell?

Answer 13

S-2, P-6, D-10, F-14

Question 14

When will electrons pair?

Answer 14

When all other orbitals in that subshell have at least one electron in them.

Question 15

Electron orbital fill order at high energy levels

Answer 15

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 4d, 4f

Question 16

How do you notate electron configuration?

Answer 16

Energy level, subshell, number of electrons:

1s²2s²2p³ (N)

Question 17

What the shorthand for electron configuration?

Answer 17

Next lowest noble gas and then state all used higher energy subshells:
[Ar] 3d²4s² (Ti)

Question 18

How do lose of electrons in d-block ions differ from elsewhere?

Answer 18

D orbital of the lower quantum energy level will empty before and fill after the S orbital of the higher energy level.

Question 19

Properties of ionic compounds.

Answer 19

High melting point due to electrostatic attraction in their crystal structure. Soluble in polar solvents due to break down of the crystal lattice when solvent molecules surround an ion. Only conductive in solution.

Question 20

What is covalent bonding?

Answer 20

The strong electrostatic attraction of nuclei to a shared pair of electrons. producing a localised attraction to form a molecule.

Question 21

What is a σ-bond?

Answer 21

A covalent bond from the direct overlap of orbitals.

Question 22

What is a π-bond?

Answer 22

A covalent bond from the lateral joining of orbitals above and below the bonding plane.

Question 23

What is a double covalent bond?

Answer 23

A bond containing a π-bond and a σ-bond involving 4 electrons.

Question 24

What is a single covalent bond?

Answer 24

A σ-bond involving 2 electrons.

Question 25

What is a triple covalent bond?

Answer 25

A bond involving 6 electrons.

Question 26

What is a dative or co-ordinate bond?

Answer 26

A covalent bond where a shared pair of electrons has been donated by a single atom from the bonding atoms.

Question 27

What is bond enthalpy?

Answer 27

The energy stored in a bond. It is the amount released when it is formed and the amount required to break it.