Exploiting chemical properties

The container must hold acid safely — meaning the metal must not react with the acid, which would dissolve the container and release potentially dangerous products.

Reactivity with acids is a chemical property. A metal with low reactivity will not undergo a chemical reaction with the acid, keeping the container intact.

The most important property is that the metal does not react with acids. Density, melting point, and flexibility are physical properties that do not determine whether the container will survive contact with acid.

We need to find the property most important for safely storing an acid — meaning the container must not be destroyed or damaged by the acid.

'Its density is lower than that of the acid' is irrelevant — density does not affect whether the metal reacts with acid or stays intact.

'It has a high melting point' is a physical property useful for high-temperature situations, not for storing acid at room temperature.

Flexibility is a useful manufacturing property but does not protect the container from chemical attack by the acid.

'It does not react with acids' is the only chemical property listed and is directly relevant — if the metal reacts with the acid, it would corrode and fail as a container.

A chemical property describes how a substance reacts or changes when it interacts with other substances — forming a new substance in the process.

When magnesium burns in oxygen, it forms magnesium oxide — a completely new substance. This transformation into a new substance is the key indicator of a chemical property.

Melting point, density, and malleability (being hammered into thin sheets) are all physical properties — the substance itself does not change into something new when these properties are observed.

Magnesium burns brightly in oxygen to form magnesium oxide is the only option describing a chemical change — the formation of a new substance.

We need to find the option that describes a chemical property — one where a new substance is formed.

Melting point is a physical property — iron melting is a change of state, not a change into a new substance. Iron is still iron after it melts.

Density is a physical property — measuring density does not change copper into anything new.

This describes malleability, a physical property — the gold changes shape but remains gold.

Magnesium burns in oxygen to form magnesium oxide describes a chemical reaction producing a new substance — this is a chemical property.