What happens when a magnesium ribbon is burnt in air? Write the balanced equation and state the type of reaction.

1. 1 · Define in one line. A chemical reaction changes reactants into new products with new properties.
2. 2 · Describe what you see. The cleaned ribbon burns with a dazzling white flame and leaves a white powder.
3. 3 · Write the balanced equation. 2Mg(s) + O₂(g) → 2MgO(s). The product is magnesium oxide.
4. 4 · Name the type. It is a combination reaction. It gives out heat and light, so it is exothermic.
5. 5 · Link to real life. The same bright white light of burning magnesium is used in fireworks.
6. 6 · Close in one line. So burning magnesium is a chemical change, because a new substance forms.

Scoring tip: Write the observation, the balanced equation with state symbols, and the type of reaction. Each one carries a mark.