An element, Q, forms a +7 oxidation state and a violet solution. It is used industrially as an oxidising agent. What can be inferred about Q?

In the final test, Xinyi gives John this puzzle: 10g of iron(III) oxide (Fe₂O₃) reacts with carbon monoxide in the blast furnace. How many grams of iron are produced? (Relative atomic masses: Fe=56, O=16)

At the scrapyard, Xinyi points at a rusted chain and says, 'That’s oxidation for you!' Which of the following is essential for the rusting of iron to occur?

A newly discovered element by John has properties similar to sodium. It reacts violently with water, forms a basic oxide, and has one valence electron. Which statement is most likely true about its location on the Periodic Table with respect to Sodium?

Xinyi investigates melting points of Period 3 elements. She notices Si has a much higher melting point than nearby elements. What best explains this observation?

Just before exiting, the floor shakes. The final question flashes: "Xinyi finds a mystery metal. It forms green solutions, can exist as both 2+ and 3+ ions, and catalyses the Haber process. Which element is it likely to be?"