Bonding

Question 1

Define electronegativity

Answer 1

A measure of the ability (tendency) of an atom to attract a pair of electrons towards itself in a covalent bond.

Question 2

State the factors that affect electronegativity

Answer 2

1. Number of protons in a nucleus
2. Distance from the nucleus
3. Amount of screening from inner electrons

Question 3

Define a covalent bond

Answer 3

When an electron from each atom made available and shared between two atoms. Similar electronegativities.

Question 4

Define an ionic bond

Answer 4

When there is a loss of one or more electrons by a metal and a gain of electrons by a non-metal. Ionic character is greater than covalent character so there is a great difference in electronegativity = polarity.

Question 5

Explain the difference between covalent character and ionic character

Answer 5

Covalent character: The partial sharing of electrons between atoms. No electronegativity difference leads to a pure covalent bond.
A small difference leads to a polar covalent bond. A large difference leads to an ionic bond.

Question 6

Describe a method to detect polarity

Answer 6

Charge a rod using wool and place it next to a stream of liquid to be tested.
A polar liquid will be deflected by the rod; a non-polar liquid will not.

Question 7

What is an ionic compound?

Answer 7

One formed when a metal and a non-metal bond. They form strong electrostatic forces of attraction between ions (ionic bond).
The ions are held in a giant lattice structure.

Question 8

What is a lattice structure?

Answer 8

The arrangement of ions in a way that minimises the repulsion between similarly charged ions and maximises the attraction between oppositely charged ions.
Giant lattices form ionic crystals.