Activity 1.1 involves burning a magnesium ribbon in air to observe a chemical reaction. When magnesium burns, it reacts with oxygen to form magnesium oxide (&&\ce{MgO}&&), producing a bright white light and leaving white ash. The chemical equation is: &&\ce{2Mg + O2 -> 2MgO}&&. This demonstrates a combustion reaction and the concept of oxidation.

When magnesium ribbon burns in air, it undergoes a vigorous exothermic reaction with oxygen. The magnesium burns with a brilliant white light (dazzling flame), producing heat and forming magnesium oxide as a white powdery ash. The grey magnesium metal transforms into white magnesium oxide powder. The reaction releases tremendous energy in the form of heat and light.

Magnesium burns with a bright white flame because the combustion reaction releases a tremendous amount of energy in the form of heat and light. The high temperature (around 3100°C) causes the emission of white light. This is an exothermic reaction where energy is released as the magnesium atoms bond with oxygen atoms.

The white powder formed after burning magnesium is magnesium oxide (&&\ce{MgO}&&). It is a white ash-like substance that forms when magnesium reacts with oxygen from the air. Magnesium oxide is a basic oxide and is heavier than the original magnesium ribbon because it contains added oxygen atoms.

Burning of magnesium is a chemical change because a new substance (magnesium oxide) is formed with different properties than the original magnesium. The change is irreversible, energy is released in the form of heat and light, and the chemical composition changes from Mg to MgO. These are all characteristics of chemical changes.

We should not look directly at burning magnesium ribbon because it produces an extremely bright white light that can damage the eyes. The intense light can cause temporary or permanent eye damage, including retinal burns and photokeratitis (similar to snow blindness). Always use protective eyewear or observe the flame indirectly through blue cobalt glass during this experiment.

The burning of magnesium is a combination reaction (also called synthesis reaction) and a combustion reaction. It is also an oxidation reaction where magnesium gains oxygen. Two or more reactants (magnesium and oxygen) combine to form a single product (magnesium oxide). It is also an exothermic reaction as it releases heat and light energy.

The balanced chemical equation for burning magnesium is: &&\ce{2Mg + O2 -> 2MgO}&&. This equation shows that 2 atoms of magnesium react with 1 molecule of oxygen gas to produce 2 formula units of magnesium oxide. The equation is balanced because there are 2 magnesium atoms and 2 oxygen atoms on both sides.

Safety precautions for Activity 1.1 include: 1) Use tongs or forceps to hold the magnesium ribbon, never hold it with bare hands. 2) Do not look directly at the bright flame; use protective eyewear. 3) Perform the experiment in a well-ventilated area. 4) Keep a safe distance from the burning ribbon. 5) Have a fire extinguisher or sand nearby. 6) Clean the magnesium ribbon with sandpaper before burning to remove the oxide coating. 7) Never use water to extinguish magnesium fires.