Ch7- Periodicity

Question 1

For a Giant Ionic Lattice, describe the:
* bonding
* the way that atoms combine
* the forces holding the particles together
* MP/BP
* Electrical Conductivity

Answer 1

* Bonding - Ionic Bonding (electrostatic attraction)
* Way that atoms combine - atoms lose and gain e-
* Forces holding particles together - strong ionic bonds between + and - ions
* MP/BP - High ; strong ionic bonds between cations and anions which require large amount of energy to overcome
* Electrical Conductivity - Doesn’t conduct electricity as solid, DOES conduct when molten/(aq) as ions are free to move

Question 2

For a Giant Covalent Structure, describe the:
* bonding
* the way that atoms combine
* the forces holding the particles together
* MP/BP
* Electrical Conductivity

Answer 2

• Bonding: Covalent
• Way that atoms combine: atoms share e-
• Forces holding the particles together: strong covalent bonds between atoms
• MP/BP- high ; strong covalent bonds between atoms which require a lot of energy to overcome
• Electrical Conductivity: does NOT conduct electricity. No ions/electrons which can move. EXCEPT Graphite.

Question 3

For a Simple Molecule, describe the:
* bonding
* the way that atoms combine
* the forces holding the particles together
* MP/BP
* Electrical Conductivity

Answer 3

• Bonding: covalent
• Way that atoms combine: atoms share electrons
• Forces holding the particles together: weak intermolecular forces between molecules
• MP/BP: Low ; weak intermolecular forces between molecules easy to break
• Electrical Conductivity: Does NOT conduct electricity. no free to move ions/electrons.

Question 4

For a Giant Metallic Lattice, describe the:
* bonding
* the way that atoms combine
* the forces holding the particles together
* MP/BP
* Electrical Conductivity

Answer 4

• Bonding: Metallic
• Way that atoms combine: atoms lose e-
• Forces holding the particles together: strong metallic bonds between ions and delocalised e-
• MP/BP: High ; strong metallic bonds between ions + delocalised e- require large amount of energy to overcome
• Electrical Conductivity: conducts electricity when solid as it contains delocalised e- which are free to move.

Question 5

What Factors affect MP of Ionic Compounds?

Answer 5

1. Charge on ions: the greater the charge, the greater the electrostatic attraction
2. Size of ions: generally, smaller the ion, the greater the electrostatic attraction.
   1. As radius of cations increases down Gr1/2, MP decreases
   2. Smaller ions can pack closer therefore have greater charge density, greater electrostatic attraction, ionic bond stronger, MP increases.

Question 6

What factors affect MP of Metallic Compounds?

Answer 6

Question 7

What factors affect MP of Simple Covalent

Answer 7

Question 8

Define 1st Ionisation Energy:

Answer 8

Question 9

What does Ionisation energy measure?

Answer 9

I.E. measures how easily an atom loses e- to form positive ions.

Question 10

What factors affect Ionisation Energy

Answer 10

Question 11

How do you identify the element using an ionisation energy graph?

Answer 11

Question 12

What is the trend in I.E. down a group?

Answer 12

Question 13

What is the trend in I.E. across a period?

Answer 13

Question 14

What is the sub-shell trend in 1st I.E.?

Answer 14

Question 15

What is the trend in BP and electronegativity in Halogens?

Answer 15

As you go down Gr7, BP increases, as the molecules are bigger, and there are more electrons, more Ar, stronger London Forces. Electronegativity decreases as Atomic Radius increases and more shielding so less attraction.

Question 16

What is the trend in reactivity in Halogens?

Answer 16

As you go down Gr7, the halogens get less reactive (larger atomic radius, therefore less nuclear attraction, so less likely to be readily accepting an electron)

Question 17

What are the different halide displacement reactions?

Answer 17

Question 18

Watch Allery Chemistry vid on Gr7 and Halogens