Bonding

Question 1

Define metallic bonding (1)

Answer 1

1. Strong electrostatic attraction between positive ions and delocalised electrons

Question 2

Define covalent bonding (1)

Answer 2

1. A covalent bond is a shared pair of electrons between two atoms

Question 3

Name 3 macromolecular structures (3)

Answer 3

1. Silicon
2. Carbon
3. Silicon dioxide

Question 4

Define ionic bonding (1)

Answer 4

1. An ionic bond is the strong electrostatic attraction between oppositely charged ions

Question 5

Define a co-ordinate bond (1)

Answer 5

1. Shared pair of electrons where both electrons come from the same atom

Question 6

Define the term electronegativity (2)

Answer 6

1. The power of an atom to attract a pair of electrons
2. In a covalent bond

Question 7

When does hydrogen bonding occur? (1)

Answer 7

Between hydrogen covalently bonded to nitrogen/oxygen/fluorine and lone pair on nitrogen/oxygen/fluorine

Question 8

Explain why a fluoride ion is larger than a sodium ion. (2)

Answer 8

1. Fluoride ion has fewer protons
2. Weaker attraction between nucleus and (outer) electrons

Question 9

Explain, in terms of structure and bonding, why the melting point of sodium fluoride is high. (2)

Answer 9

1. (Electrostatic) forces of attraction between
   oppositely charged ions/Na+ and F–
2. Lots of energy required to overcome forces

Question 10

How does hydrogen bonding arise? (2)

Answer 10

1. Large difference in electronegativity between hydrogen and N/O/F which creates a dipole in the H-N/O/F bond
2. partially positive H on one molecule is attracted to lone pair of N/O/F on another molecule

Question 11

When do permanent dipole dipole forces arise? (1)

Answer 11

1. Between polar molecules

Question 12

How do permanent dipole dipole forces arise? (3)

Answer 12

1. Differences in electronegativity lead to polar bonds
2. In non-symmetrical molecules, the individual bonds don’t cancel out
3. Partially positive H on one molecule attracts partially negative on another molecule

Question 13

When do induced dipole dipole forces occur? (1)

Answer 13

1. Between all molecules and atoms

Question 14

How do induced dipole dipole forces (Van der Waals) arise? (5)

Answer 14

1. Random movement of electrons, leading to
2. Uneven distribution of electrons, creating a
3. Temporary dipole in one molecule
4. Induces a dipole in another molecule
5. Dipoles attract