3.1.3 Bonding

Question 1

What is ionic bonding?

Answer 1

the electrostatic attraction between oppositely charged ions in an ionic lattice structure

Question 2

Why are the ions in ionic bonding arranged in a lattice structure?

Answer 2

ensures there is electrostatic attraction between the oppositely charged ions

Question 3

How can the ionic lattice break?

Answer 3

. Physical stress (by force)
. Dissolving
. Heating

Question 4

What are the properties of ionic compounds?

Answer 4

. High melting and boiling point
- many strong electrostatic forces of attraction between oppositely charged ions
- in the ionic lattice
- need lots of energy to overcome these attractions

. Conducts electricity with molten
- when molten ions are free to move so carry charge

. Brittle (breaks easily)
- if force is applied, the layers of ions move, making the ions of the same charge next to each other
- The layers repel each other, and the crystal breaks

Question 5

Strength of ionic bonding.

Answer 5

The smaller the ion - the greater the charge of the ions - the stronger the attraction between the positive and negative ions

Question 6

Factors affecting the strength of ionic compounds.

Answer 6

• Charge of ion
• Radii of the ion

Question 7

What is metallic bonding?

Answer 7

The electrostatic attraction between delocalised electrons and positively charged metal ions arranged in a giant metallic lattice

Question 8

What are the properties of metallic bonding?

Answer 8

. Conducts electricity ( solid and molten)
-contains delocalised electrons, which are the mobile charge carriers which carry the current

. Malleable (can be bent) and . Ductile (can be drawn into long thin wires)

-layers of metal ions slide over one another

Question 9

Why does gaseous metal not conduct electricity?

Answer 9

. A sample of gaseous metal contains gaseous metal atoms not ions
-no delocalised electrons therefore cannot conduct electricity

for example plasma

Question 10

Factors effecting strength of metallic bonding.

Answer 10

1) the charge on the metal ion
-the greater the charge on the metal ions
-the greater the attractions between the ions and each delocalised electrons
-stronger the metallic bond
-MP and BP are higher as more energy is needed to overcome the forces of attraction

2) the size of the metal ions
-the smaller the metal ion - closer the positive nucleus is to the delocalised electron
-greater attraction = stronger bond

Question 11

How are the particles arranged in a metal lattice and show the charges on the particles?

Answer 11

Regular arrangement of the +ve ions

-ve delocalised electrons around

Question 12

What is covalent bonding?

Answer 12

Strong electrostatic attraction between shared pairs of electrons and the nuclei of the bonded atoms in a macromolecular structure

Question 13

What is a dative covalent bond?

Answer 13

forms when the shared pair of electrons in a covalent bond come from only one of the bonding atoms

Question 14

What are the four types of crystal structures?

Answer 14

1) Ionic
2) Metallic
3) Molecular
4) Macromolecular (diamond…)

Question 15

What is electronegativity?

Answer 15

the power of an atom to attract a pair of electrons in a covalent bond

Question 16

How does electronegativity determine what bond atoms will make?

Answer 16

. two elements of similar electronegativity will form a covalent bond
. two elements that have very different electronegativity will form an ionic bond

Question 17

What factors affects electronegativity and why?

Answer 17

. Nuclear charge
-more protons = greater nuclear charge = stronger attraction between nucleus and bonding pair of electrons

. Atomic radius
-the smaller the atomic radius the closer the bonding pair of electrons = stronger attraction between the nucleus and the bonding pair in the covalent bond

. Shielding
-electrons in each shell repel each other
-full electron shells shield bonding pair electrons from the attraction of the nucleus
- more electron shells = greater shielding effect = weaker attraction between nucleus and pair of electrons in the covalent bond