(a) The diagram shows the structure of diamond - Edexcel - GCSE Chemistry - Question 5 - 2014 - Paper 1

The type of bonding in the diamond structure is covalent bonding, where each carbon atom shares electrons with four neighboring carbon atoms, resulting in a very strong structure.

The process used to obtain oxygen from liquid air is called fractional distillation.

The Rf value of the dye can be calculated using the formula:

$Rf = \frac{distance\ moved\ by\ dye}{distance\ moved\ by\ solvent}$

Substituting the values: $Rf = \frac{2\ cm}{8\ cm} = 0.25$

Therefore, the correct answer is A (0.25).

To carry out the reaction between magnesium and oxygen to form magnesium oxide (MgO), follow these steps:

1. Setting up the apparatus: Place a piece of magnesium ribbon in a heat-resistant dish (like a crucible) and ensure you have a Bunsen burner ready.

2. Igniting the magnesium: Using tongs, hold the magnesium ribbon and ignite it in a Bunsen flame. Be cautious as the reaction is highly exothermic and will emit bright white light.

3. Observing the reaction: Once the magnesium burns, it reacts with oxygen in the air, forming magnesium oxide, which appears as a white powder or solid.

4. Understanding the bonding: Magnesium atoms have 2 electrons in their outer shell and tend to lose these electrons to achieve a stable electron configuration. When magnesium burns in the presence of oxygen, it forms MgO by transferring its electrons to the oxygen atoms. Oxygen atoms have 6 electrons in their outer shell and need 2 more to complete it. Therefore, they gain 2 electrons from magnesium, forming Mg²⁺ ions and O²⁻ ions. These oppositely charged ions attract each other and form ionic bonds, resulting in magnesium oxide.